Rise of Shadows: Arena Impact

Rise of Shadows is Hearthstone's eleventh expansion and is set to release on April 9, 2019.

New Keyword: Twinspell - You get a second copy of the spell (without the Twinspell keyword).
Schemes - Spells that get more powerful the longer you hold them in your hand.
Lackeys - These are 1/1 tokens created by other cards that have a variety of Battlecry abilities, such as dealing damage, giving other minions Attack/Health bonuses, or summoning new minions. More will be introduced throughout the year.
Old Mechanics: Look for some old mechanics that haven't been used in awhile to make a resurgence throughout the year.  We'll definitely be seeing the "Forbidden" mechanic from Whispers of the Old Gods where you are required to spend all of your mana to play the card (Forbidden: Ancient, Flame, Shaping, Ritual, and Healing).
Arena: The cardpool availability will change to include the following sets: Basic, Classic, Naxxramas, Whispers of the Old Gods, Goblins VS Gnomes, The Witchwood, and Rise of Shadows.
Pre-Order: $50 and $80 options will be available for pre-order and both come with the new card back "The Jewel of Lazul" shown below.

This thread is dedicated to discussing the impact of these cards on the ARENA environment.

Click below to see how each of the Arena Mods rated the cards revealed so far!

You can read each Mod's detailed card evaluation by clicking on the links below.

Below you will find links for all of the cards that have been revealed so far.

Update 3/14/19: Created initial thread.
Update 3/15/19: Added Arch-Villain Rafaam, Chef Nomi, Kalecgos, Forbidden Words, Hagatha's Scheme, Spellward Jeweler, The Forest's Aid, Togwaggle's Scheme, and EVIL Miscreant.
Update 3/19/19: Added Swampqueen Hagatha, Oblivitron, and Lazul's Scheme.
Update 3/21/19: Added Improve Morale, Omega Devastator, and Rafaam's Scheme.
Update 3/22/19: Added Madame Lazul.
Update 3/25/19: Added Clockwork Goblin, EVIL Cable Rat, Dr. Boom's Scheme, Blastmaster Boom, Wrenchcalibur, Heistbaron Togwaggle, Hench-Clan Burglar, Unidentified Contract, [Hearthstone Card (Travelling Healer) Not Found], Khadgar, Power of Creation, and Messenger Raven.
Update 3/26/19: Added Lightforged Blessing, Unleash the Beast, Keeper Stalladris, Never Surrender!, EVIL Genius, EVIL Conscripter, and Vereesa Windrunner.
Update 3/27/19: Added Hench-Clan Hogsteed, Jepetto Joybuzz, Dragon Speaker, Bronze Herald, Mass Resurrection, and Sludge Slurper.
Update 3/28/19: Added Crystal Stag, Crystal Power, Fel Lord Betrug, Hecklebot, Muckmorpher, and Walking Fountain.
Update 3/29/19: Added Commander Rhyssa, Ray of Frost, Mana Cyclone, Nozari, Unseen Saboteur, Shadowy Figure, and Duel!.
Update 3/31/19: Added Marked Shot, Catrina Muerte, Batterhead, Eager Underling, Magic Trick, Crystalsong Portal, Acornbearer, Vendetta, Nine Lives, Plot Twist, Dreamway Guardians, and Lifeweaver.
Update 4/1/19: Added Archmage Vargoth, Tak Nozwhisker, Desperate Measures, Big Bad Archmage, Call to Adventure, Underbelly Fence, Lucentbark, and Aranasi Broodmother.
Update 4/2/19: Added Dimensional Ripper, Shimmerfly, Hench-Clan Hag, and Archivist Elysiana.
Update 4/3/19: Added Barista Lynchen, Exotic Mountseller, The Boom Reaver, Conjurer's Calling, and the rest of the cards from the reveal stream.

This is a work in progress!

DRUID

HUNTER

MAGE

PALADIN

PRIEST

ROGUE

SHAMAN

WARLOCK

WARRIOR

NEUTRAL

[Hearthstone Card (Travelling Healer) Not Found]

Legendary

Archivist Elysiana Rating 4(Poor): This just seems like a bad idea.  You can Discover some absolute garbage, so I think I would stick with the deck I drafted in the first place.

Archmage Vargoth Rating 3(Average): I think he gets bumped up in ranking if you have a spell-heavy deck.  He's large enough to survive a turn or two and could give some amazing value, especially with stuff like Arcane Intellect.

Arch-Villain Rafaam Rating 1(Excellent): I like it!  It's a large Taunt that is reasonably priced and you could get some awesome value from it as long as the RNG doesn't stick you with a deck full of Lorewalker Cho.

Barista Lynchen Rating 3(Average): You can certainly get some great value from this, but it's just going to depend on the board state.  I think she's okay if you play her with no effect and although she's slightly overcosted the stats are still good.

Blastmaster Boom Rating 3(Average): I initially thought this was nearly identical to the original Dr. Boom, but it has the potential (probably not in Arena) to be better.  At worst it's still a 7/7 body for 7 mana and that's not terrible.

Catrina Muerte Rating 1(Excellent): The recursion this card offers, for FREE mind you, is simply amazing!  The fact that it isn't easily killed is another big plus for this minion.

Chef Nomi Rating 4(Poor): This would have very limited use in Arena and it's otherwise overcosted to play as just a body on the board.

Commander Rhyssa Rating 3(Average): Unless you've got a Secret-heavy deck, this probably won't have a huge impact.  By itself it's fine as a 3-drop.

Fel Lord Betrug Rating 2(Good): It has decent stats and gives a lot of value with free Rush minions.  My only complaint is that he gives away everything you draw, so there can be no more bluffs or surprises with him on the board.

Heistbaron Togwaggle Rating 4(Poor): It's situational, but could go up in value depending on your draft.  That rating also assumes that the "Fantastic Treasures" are actually good!

Jepetto Joybuzz Rating 3(Average): This is only worth it if you draw something with a Battlecry or Deathrattle, otherwise it's pretty underwhelming.

Kalecgos Rating 2(Good): This card is great on the first turn.  However, beyond that, unless you have quite a few spells, it just may not perform quite as well as you would like for it to.

Keeper Stalladris Rating 3(Average): I think this will be okay as a standard 2-drop, but the bonus is going to be pretty situational.

Khadgar Rating 3(Average): This is another situational one, but it seems okay as a basic 2-drop in a worst-case scenario.

Lucentbark Rating 3(Average):  He's a fairly large wall, but you really got to be able to wake him from his dormant state to take full advantage of him.  This is another clear indication they really want Druid players to start healing themselves.

Madame Lazul Rating 2(Good): This gives some good intel in regards to what your opponent has in his hand.  If they have less than 3 cards it might not be as valuable, but definitely still useful.

Nozari Rating 4(Poor): It's great if you're fighting from behind, but a Reno Jackson for both players isn't normally what you're looking for in an Arena match.

Oblivitron Rating 5(Terrible):  The stars have to be aligned in order for this to work in Arena.  If it were for Beasts instead of Mechs I might fold a little bit, but this has pretty narrow flexibility and way too expensive to cast as a simple 3/4 body.

Scargil Rating 3(Average):  It's probably not going to be very useful in Arena, but a 4/4 body for four mana will do just fine.

Swampqueen Hagatha Rating 1(Excellent): It's a little slow, but you can definitely get some value out of this one.

Tak Nozwhisker Rating 4(Poor): It probably won't have consistent opportunities to copy cards in Arena and is otherwise just going to be a slightly overcosted minion most of the time.

The Boom Reaver Rating 3(Average): Even if you roll low you'll probably end up around 9/12 worth of combined stats - which is nothing to ignore.  I'm concerned about how slow it is and that RNG needs to be in your favor to have an immediate impact.

Vereesa Windrunner Rating 2(Good): Getting a 5/6 body and a 2/3 Weapon for only 7 mana is a pretty good deal.

Epic

Arcane Fletcher Rating 4(Poor): You might have a couple of 1-cost minions, but this is situational, at best.

Azerite Elemental Rating 4(Poor): If you could protect it for several turns it could be crazy in the right deck, but slow and lackluster the rest of the time.

Batterhead Rating 3(Average): If you're facing a board of small minions it could come in handy, but if your opponent has a Taunt out it might be an expensive disappointment.

Big Bad Archmage Rating 3(Average): It's really expensive, but you can get some great value out of it once you've ran out of options.

Crystalsong Portal 1(Excellent): Wow!  Your hand doesn't even have to be empty - just as long as you don't have any minions it will work.

Crystal Stag Rating 3(Average): You probably won't see many duplicates in Arena, but having Rush on this minion is decent.

Darkest Hour Rating 4(Poor): It's another bid to RNG that you'll never want to use unless you've got a board full of tokens or just desperately outmatched on the board.

Dragon Speaker Rating 4(Poor): It's pretty situational for Arena, but could definitely go up in ranking if your deck supports it.

Duel! Rating 5(Terrible): I just think this is a bad idea unless you've got a deck full of Divine Shield or Poisonous minions.

Hench-Clan Hag Rating 1(Excellent): You get 5/5 worth of combined stats for only 4 mana!  Sign me up!

Jumbo Imp Rating 2(Good): Warlock has no shortage of Demons and I wouldn't be surprised to see this make an appearance in the mid-game on a regular basis.

Lazul's Scheme Rating 3(Average): It's a cool card that can let you make some beneficial trades or outright kill a minion for free.  I also expect some Mind Control effect shenanigans to pop up every so often.

Magic Carpet Rating 4(Poor): I don't know that it's unplayable, but it's pretty trashy unless you've got a very specific type of deck.

Mana Cyclone Rating 3(Average): It's fine if you want to play it as a 2-drop, but has the potential to get some additional value later in the game.

Muckmorpher Rating 4(Poor): I'm not sure how useful the Battlecry will be in Arena.  It may have no immediate impact other than letting your opponent know at least one other minion you have included in your deck.

Nine Lives Rating 3(Average): It's definitely situational, but when it works it's pretty good!

Omega Devastator Rating 1(Excellent):  It's a Yeti with an upside, so it's a pretty good deal.  The stats are good enough on their own, but this card really shines in the late game.

Portal Overfiend Rating 3(Average): When compared to [Hearthstone Card (Faldorei Strider) Not Found] it seems sorta meh, but I still think it has decent stats and the Rush ability on the minions could come in handy.

Power of Creation Rating 2(Good): That is some serious value, especially if you Discover anything over 4/4 or with a Battlecry.

Shadowy Figure Rating 3(Average): This is another one that's fine as a 2-drop, but has the potential to improve, depending on the board state.

Unidentified Contract Rating 2(Good): I'm not sure what the bonus effects are, but for Rogue to get removal without conditions and the potential of something extra is a good thing.

Unseen Saboteur Rating 3(Average): I really like the disruption this card causes, but the RNG could work against you.  Keep in mind that for any non-targeted spells you've probably just given them an advantage, especially if it's something like Arcane Intellect.

Waggle Pick Rating 2(Good): It's a good-sized Weapon and you get a (discounted) minion back from the Deathrattle.  Not a bad deal!

Whirlwind Tempest Rating 4(Poor): It could be a great surprise finisher if you've already got a Windfury minion on the board.

Witch's Brew Rating 4(Poor): Healing is usually not high on the consideration part for Arena decks, but I can see this being super frustrating when your opponent heals himself for 20 Health in the late game.  It's possibly more obnoxious than Healing Rain.

Wrenchcalibur Rating 3(Average): It's not amazing by itself, but it's still a decent weapon that can generate 10 potential additional damage to your opponent.

Rare

Arcane Watcher Rating 5(Terrible): I don't think I'll be drafting this any time soon.  It's pretty awful for Arena.

Call to Adventure Rating 4(Poor): This just doesn't feel good to me.  You may not be able to cast it right away unless you're mid-late game and by then it might not matter.  I think I'll just stick with Blessing of Kings, thanks.

Clockwork Goblin Rating 3(Average): It's fine as a 3-drop and tossing the Bomb in your opponent's deck is a bonus.

Conjurer's Calling Rating 1(Excellent):  You can use this on a minion that's about to die and get some amazing value and then use it again because of Twinspell!

Convincing Infiltrator Rating 2(Good): This is going to be really annoying when facing Priest because you'll want to avoid it, but you can't because of the Taunt.

Desperate Measures Rating 3(Average): Typically, Paladin Secrets aren't amazing, but the Twinspell makes this fairly decent overall.

Dreamway Guardians Rating 1(Excellent): Getting 2/4 worth of combined stats with Lifesteal for only two mana is pretty amazing.

Dimensional Ripper Rating 4(Poor): There is a good chance you blow your entire turn getting a couple of mediocre minions.  It doesn't seem worth it to me.

Eager Underling Rating 2(Good): This is another that has a great, situational effect.  It's certainly going to cause disruption for your opponent since they won't want to kill it until they've removed any minions it could buff.

Exotic Mountseller Rating 3(Average): It's slow, but it's got decent stats and nice ability if you've got the spells to support it.  It will really depend on your draft if you decide to include this minion.

Forbidden Words Rating 3(Average): I can see this being extremely frustrating.  Not because you may have to wait a turn to get rid of something, but because it completely kills your turn.  You will likely have to spend all of your mana to kill one thing and won't be able to do anything else to establish your board.

Hagatha's Scheme Rating 1(Excellent): I don't like that it kills your board too, but it's a pretty amazing and powerful piece of removal!

Hecklebot Rating 4(Poor): He is a fairly large Taunt, but giving your opponent a random, free minion is usually a bad idea.

Hunting Party Rating 5(Terrible): This is going to be too expensive/situational for an Arena deck.

Impferno Rating 2(Good): It will be situational whether or not it buffs anything for you, but the 1 damage only hits your opponent's minions, so that's worth something.

Kirin Tor Tricaster Rating 3(Average): Giving yourself more expensive spells is not what you want to see in a card.  However, having +3 Spell Damage could be devastating for your opponent.

Lifeweaver Rating 3(Average): The effect is great, but you typically don't have that much healing floating around for Druid.  Although it looks like some of the new cards may be pushing towards that.

Mad Summoner Rating 4(Poor): It goes so nicely with Impferno, but unlikely to happen often enough to draft it.

Magic Trick Rating 3(Average): I like the Discover aspect, but you're still ultimately paying an extra mana for a spell that may have a minor impact on the game.  It's going to be fairly situational, but you could have some good moments.

Mass Resurrection Rating 4(Poor): You're at the mercy of RNG and since it's a late-game card you run the risk and summoning early game minions that are not going to be very helpful.

Mysterious Blade Rating 3(Average): I think it's fine on its own, but really shines if you have a Secret on the board.

Plot Twist Rating 3(Average): It's a cheap replacement effect, but it's a coin toss to RNG.  You're definitely not guaranteed to get anything better and you may even get the same cards back.

Portal Keeper Rating 3(Average):  The effect is identical to Portal Overfiend, but the cost and stats are different.  It's unlikely to survive long since it only has 2 Health, but the Rush minions still count for something.

Recurring Villain Rating 4(Poor): It could be mildly interesting in the right deck, but I think I'll pass.

Shimmerfly Rating 3(Average): It's like the brother for Jeweled Macaw and it has the potential to give you something really good.  On its own it's fine as a one-drop, especially with the Beast tag.

Sludge Slurper Rating 1(Excellent): You can get some great value out of this with the Lackey and the Overload impact is minimal.  Considering you'll still be able to cast the Lackey you just drew on your following turn I think this has the potential to be a real troublemaker.

Spellward Jeweler Rating 2(Good): The stats are good and it could cause some frustration for your opponent, which is always fun.

Sunreaver Warmage Rating 3(Average): Depending on your deck, this could be awesome and would definitely go up in value if you're spell-heavy.

Sweeping Strikes Rating 3(Average): This could be absolutely devastating, especially if your opponent is dug in behind a Taunt.  It won't always be amazing because you've got to have a decent minion to throw it on to start with.

The Forest's Aid Rating 2(Good): It's expensive, but you're getting 10/10 worth of combined stats for only 8 mana.  That's a bargain!  Of course, any AoE is just going to absolutely wreck you.

Togwaggle's Scheme Rating 4(Poor): This seems extremely situational to me.  You need a decent target first and that is never guaranteed.  You may also seal your own fate by forcing yourself to keep drawing a minion that is no longer useful against your opponent and you can't draw any of your removal because your deck is completely stuffed with a mediocre minion.

Tunnel Blaster Rating 3(Average): It might come in handy if you're playing from behind, but otherwise it's going to blow up your side of the board too.

Underbelly Angler Rating 3(Average): It's fine as a regular two-drop, but in the right deck this easily moves up in ranking as it will generate a ton of additional minions.

Underbelly Fence Rating 3(Average): It definitely goes up in ranking if you have several cards that allow you to "burgle" your opponent's cards, but otherwise it makes a fine two-drop.

Underbelly Ooze Rating 4(Poor): It's probably too slow for Arena but can certainly get out of hand in the right deck.

Unleash the Beast Rating 3(Average):  I feel cheated with this after looking at Militia Commander, but the Twinspell counts for something and having another big minion in your pocket isn't a bad thing.

Vendetta Rating 2(Good): I think it's good as is, but if you manage to get it for free, then it's great!

Common

Acornbearer Rating 3(Average): I think getting 4/3 worth of combined stats for three mana is typical, so it's nothing amazing.

Aranasi Broodmother Rating 3(Average): It's a decent-sized minion with Taunt and heals are always welcome in Warlock.

Arcane Servant Rating 3(Average): It's nothing special, but at least it has an Elemental tag.

Blessing of the Ancients Rating 3(Average): It could be really nice mid-game with the Twinspell aspect.

Bronze Herald Rating 2(Good): Unless it's hit with a Silence it can generate some great value, allowing you to put out some nice mid-range minions for a couple of turns.

Burly Shovelfist Rating 2(Good): It's expensive, but the Rush ability with its size is nothing to ignore.

Crystal Power Rating 3(Average): It's cheap and flexible, giving you the option of removal or healing.

Dalaran Crusader Rating 2(Good): I can see this is going to be really annoying to deal with.

Dalaran Librarian Rating 3(Average): It's much more of a constructed card, but will be fine if played on curve as a regular 2-drop.

Daring Escape Rating 5(Terrible): It's not often you'll find a situation you want to return ONLY your minions to your hand in Arena.

Dr. Boom's Scheme Rating 4(Poor): This is so slow and dull.  It can definitely have it's uses, but I would rather not hold onto a single card for an entire Arena game just to gain a massive amount of Armor.

Eccentric Scribe Rating 2(Good) You end up getting 10/8 of combined stats for only 6 mana which is awesome!  I'm reserving final judgment until we find out what the Vengeful Scrolls that get summoned do.

EVIL Cable Rat Rating 3(Average): You're getting 2/2 worth of combined stats with a random Battlecry for 3 mana.  I think it's alright.

EVIL Conscripter Rating 3(Average): I think it's alright as long as you get a decent Lackey.

EVIL Genius Rating 3(Average): It sounds like a really good deal, but you're still destroying one of your other minions, so you're rolling the dice to get some Lackey love from the Battlecry.

EVIL Miscreant Rating 2(Good): You're getting 3/7 worth of combined stats for a minimum of 4 mana, which is nothing to frown upon.  Not to mention, you've also got a couple of Battlecries from the Lackeys that could prove useful.

Faceless Rager Rating 3(Average): It's good to see Ragers getting some more love and it's about as good as you would expect it to be.  Although, it could be a real problem in the mid-late game once you start putting larger minions on the board.

Flight Master Rating 1(Excellent): I generally don't like giving my opponent anything, but you're getting 5/6 worth of combined stats for only 3 mana.  That is amazing!  If you're able to take care of the 2/2 your opponent gets without trading in your own 2/2, then you've gained a huge advantage.

Hench-Clan Burglar Rating 3(Average): The stats are alright, but I really like how they changed the Discover aspect.  Going forward other new Rogue cards will be discovered in this same way instead of only from your opponent's class.

Hench-Clan Hogsteed Rating 3(Average): I think the stats are alright and the Rush is nice, but it's nothing too crazy.

Hench-Clan Shadequill Rating 2(Good): This goes back to the Zombie Chow mentality, but since it's more expensive it's not nearly as amazing.  Looking at Chillwind Yeti sort of puts it in perspective.

Hench-Clan Sneak Rating 3(Average): Seems like a typical, average card to me.

Heroic Innkeeper Rating 3(Average): You need at least 2 other minions already on the board to make it worth it.  That shouldn't be hard to do, but if you aren't able to buff it, then it's going to be a real disappointment.

Improve Morale Rating 3(Average): I like the cheap removal, but you almost want your target to survive so you can get the Lackey too.

Lightforged Blessing Rating 4(Poor): Evidently they want Paladins to heal a lot more.  Ultimately you still need a body to put this on or it's just a waste.  I think I'd rather have a minion in this slot even though it's likely to be an annoying spell, especially with the Twinspell aspect.

Magic Dart Frog Rating 3(Average): It's like Flamewaker's baby brother.

Mana Reservoir Rating 5(Terrible):  It's only a threat if you've got the spells to support it.

Marked Shot Rating 1(Excellent): I think the 4 damage is fine, but getting to Discover a spell along with it is astounding!

Messenger Raven Rating 3(Average): The stats are so-so, but discovering another minion can certainly come in handy.

Mutate Rating 3(Average): It's like the discount version of Unstable Evolution.

Never Surrender! Rating 2(Good): This will be more difficult to test for than most other Paladin secrets and in Arena your opponent may not have an effective way to do that.  This absolutely wrecks AoE like Consecration and Flamestrike.

Potion Vendor Rating 3(Average): The effect is nice, but the minion is so small it will difficult to really be happy when you've drawn it.

Proud Defender Rating 3(Average): It can be pretty good if you've got an empty board, but it's awkward to keep out there.

Rafaam's Scheme Rating 3(Average): This is one that may be fairly situational, depending on the board state, but it's still decent.

Rapid Fire Rating 3(Average): It's nice to get a small ping with Twinspell.  It could come in handy.

Ray of Frost Rating 3(Average): This card has a lot of flexibility by letting you delay attacks from your opponent or destroy small, troublesome minions.

Safeguard Rating 3(Average): I feel sorta 'meh' about this, but I really think it's going to be awfully annoying considering your opponent has to waste 10 damage to get through the wall.

Soldier of Fortune Rating 5(Terrible): No way do you want to keep tossing your opponent Coins.  This would actually be perfect with Unsleeping Soul, but otherwise not worth it.

Soul of the Murloc Rating 3(Average): It's like a cheaper, less threatening version of Soul of the Forest.

Spellbook Binder Rating 3(Average): It's still fine as a 2-drop even if you don't get to draw an extra card.

Sunreaver Spy Rating 3(Average): It's another one of those that's alright as a 2-drop, but gets better if you meet the special condition.

Toxfin Rating 4(Poor): This will really depend on your draft, but most of the time I would pass.

[Hearthstone Card (Travelling Healer) Not Found] Rating 3(Average): Because this has Divine Shield it may actually be a little better than Average.  I'm still undecided on it.

Unsleeping Soul Rating 4(Poor): This is only going to be useful in certain situations.  The Silence effect just absolutely kills it.

Ursatron Rating 3(Average): It's nice if you can get the Deathrattle bonus, but even so, it's fine as a normal 3-drop.

Vicious Scraphound Rating 3(Average): I can see these little guys gaining ridiculous amounts of Armor if they're hid behind a Taunt.  Otherwise, they should be pretty easy to deal with.

Violet Spellsword Rating 4(Poor):  It's really going to depend on your draft as to how consistent this minion is.

Violet Warden Rating 2(Good): It's a large, reasonably-priced Taunt with Spell Damage.  That's some hefty power-creep on Archmage and I'll take it!

Walking Fountain Rating 1(Excellent): This guy is big and can turn a game around in a hurry.  I can see his Lifesteal ability being super frustrating, especially when it can take out a couple of mid-sized minions and still be left standing.

Swampqueen Hagatha Rating 1(Excellent): It's a little slow, but you can definitely get some value out of this one.

Oblivitron Rating 5(Terrible):  The stars have to be aligned in order for this to work in Arena.  If it were for Beasts instead of Mechs I might fold a little bit, but this has pretty narrow flexibility and way too expensive to cast as a simple 3/4 body.

Lazul's Scheme Rating 3(Average): It's a cool card that can let you make some beneficial trades or outright kill a minion for free.  I also expect some Mind Control effect shenanigans to pop up every so often.

Omega Devastator Rating 1(Excellent):  It's a Yeti with an upside, so it's a pretty good deal.  The stats are good enough on their own, but this card really shines in the late game.

Improve Morale Rating 3(Average): I like the cheap removal, but you almost want your target to survive so you can get the Lackey too.

Rafaam's Scheme Rating 3(Average): This is one that may be fairly situational, depending on the board state, but it's still decent.

Madame Lazul Rating 2(Good): This gives some good intel in regards to what your opponent has in his hand.  If they have less than 3 cards it might not be as valuable, but definitely still useful.

Blastmaster Boom Rating 3(Average): I initially thought this was nearly identical to the original Dr. Boom, but it has the potential (probably not in Arena) to be better.  At worst it's still a 7/7 body for 7 mana and that's not terrible.

Heistbaron Togwaggle Rating 4(Poor): It's situational, but could go up in value depending on your draft.  That rating also assumes that the "Fantastic Treasures" are actually good!

Khadgar Rating 3(Average): This is another situational one, but it seems okay as a basic 2-drop in a worst-case scenario.

Power of Creation Rating 2(Good): That is some serious value, especially if you Discover anything over 4/4 or with a Battlecry.

Unidentified Contract Rating 2(Good): I'm not sure what the bonus effects are, but for Rogue to get removal without conditions and the potential of something extra is a good thing.

Wrenchcalibur Rating 3(Average): It's not amazing by itself, but it's still a decent weapon that can generate 10 potential additional damage to your opponent.

Clockwork Goblin Rating 3(Average): It's fine as a 3-drop and tossing the Bomb in your opponent's deck is a bonus.

Dr. Boom's Scheme Rating 4(Poor): This is so slow and dull.  It can definitely have it's uses, but I would rather not hold onto a single card for an entire Arena game just to gain a massive amount of Armor.

EVIL Cable Rat Rating 3(Average): You're getting 2/2 worth of combined stats with a random Battlecry for 3 mana.  I think it's alright.

Hench-Clan Burglar Rating 3(Average): The stats are alright, but I really like how they changed the Discover aspect.  Going forward other new Rogue cards will be discovered in this same way instead of only from your opponent's class.

Messenger Raven Rating 3(Average): The stats are so-so, but discovering another minion can certainly come in handy.

Travelling Healer Rating 3(Average): Because this has Divine Shield it may actually be a little better than Average.  I'm still undecided on it.

Keeper Stalladris Rating 3(Average): I think this will be okay as a standard 2-drop, but the bonus is going to be pretty situational.

Unleash the Beast Rating 3(Average):  I feel cheated with this after looking at Militia Commander, but the Twinspell counts for something and having another big minion in your pocket isn't a bad thing.

Lightforged Blessing Rating 4(Poor): Evidently they want Paladins to heal a lot more.  Ultimately you still need a body to put this on or it's just a waste.  I think I'd rather have a minion in this slot even though it's likely to be an annoying spell, especially with the Twinspell aspect.

Never Surrender! Rating 2(Good): This will be more difficult to test for than most other Paladin secrets and in Arena your opponent may not have an effective way to do that.  This absolutely wrecks AoE like Consecration and Flamestrike.

Vereesa Windrunner Rating 2(Good): Getting a 5/6 body and a 2/3 Weapon for only 7 mana is a pretty good deal.

EVIL Conscripter Rating 3(Average): I think it's alright as long as you get a decent Lackey.

EVIL Genius Rating 3(Average): It sounds like a really good deal, but you're still destroying one of your other minions, so you're rolling the dice to get some Lackey love from the Battlecry.

Jepetto Joybuzz Rating 3(Average): This is only worth it if you draw something with a Battlecry or Deathrattle, otherwise it's pretty underwhelming.

Dragon Speaker Rating 4(Poor): It's pretty situational for Arena, but could definitely go up in ranking if your deck supports it.

Mass Resurrection Rating 4(Poor): You're at the mercy of RNG and since it's a late-game card you run the risk and summoning early game minions that are not going to be very helpful.

Sludge Slurper Rating 1(Excellent): You can get some great value out of this with the Lackey and the Overload impact is minimal.  Considering you'll still be able to cast the Lackey you just drew on your following turn I think this has the potential to be a real troublemaker.

Bronze Herald Rating 2(Good): Unless it's hit with a Silence it can generate some great value, allowing you to put out some nice mid-range minions for a couple of turns.

Hench-Clan Hogsteed Rating 3(Average): I think the stats are alright and the Rush is nice, but it's nothing too crazy.

Fel Lord Betrug Rating 2(Good): It has decent stats and gives a lot of value with free Rush minions.  My only complaint is that he gives away everything you draw, so there can be no more bluffs or surprises with him on the board.

Crystal Stag Rating 3(Average): You probably won't see many duplicates in Arena, but having Rush on this minion is decent.

Muckmorpher Rating 4(Poor): I'm not sure how useful the Battlecry will be in Arena.  It may have no immediate impact other than letting your opponent know at least one other minion you have included in your deck.

Hecklebot Rating 4(Poor): He is a fairly large Taunt, but giving your opponent a random, free minion is usually a bad idea.

Crystal Power Rating 3(Average): It's cheap and flexible, giving you the option of removal or healing.

Walking Fountain Rating 1(Excellent): This guy is big and can turn a game around in a hurry.  I can see his Lifesteal ability being super frustrating, especially when it can take out a couple of mid-sized minions and still be left standing.

Commander Rhyssa Rating 3(Average): Unless you've got a Secret-heavy deck, this probably won't have a huge impact.  By itself it's fine as a 3-drop.

Nozari Rating 4(Poor): It's great if you're fighting from behind, but a Reno Jackson for both players isn't normally what you're looking for in an Arena match.

Duel! Rating 5(Terrible): I just think this is a bad idea unless you've got a deck full of Divine Shield or Poisonous minions.

Mana Cyclone Rating 3(Average): It's fine if you want to play it as a 2-drop, but has the potential to get some additional value later in the game.

Shadowy Figure Rating 3(Average): This is another one that's fine as a 2-drop, but has the potential to improve, depending on the board state.

Unseen Saboteur Rating 3(Average): I really like the disruption this card causes, but the RNG could work against you.  Keep in mind that for any non-targeted spells you've probably just given them an advantage, especially if it's something like Arcane Intellect.

Ray of Frost Rating 3(Average): This card has a lot of flexibility by letting you delay attacks from your opponent or destroy small, troublesome minions.

Catrina Muerte Rating 1(Excellent): The recursion this card offers, for FREE mind you, is simply amazing!  The fact that it isn't easily killed is another big plus for this minion.

Batterhead Rating 3(Average): If you're facing a board of small minions it could come in handy, but if your opponent has a Taunt out it might be an expensive disappointment.

Crystalsong Portal 1(Excellent): Wow!  Your hand doesn't even have to be empty - just as long as you don't have any minions it will work.

Nine Lives Rating 3(Average): It's definitely situational, but when it works it's pretty good!

Dreamway Guardians Rating 1(Excellent): Getting 2/4 worth of combined stats with Lifesteal for only two mana is pretty amazing.

Eager Underling Rating 2(Good): This is another that has a great, situational effect.  It's certainly going to cause disruption for your opponent since they won't want to kill it until they've removed any minions it could buff.

Lifeweaver Rating 3(Average): The effect is great, but you typically don't have that much healing floating around for Druid.  Although it looks like some of the new cards may be pushing towards that.

Magic Trick Rating 3(Average): I like the Discover aspect, but you're still ultimately paying an extra mana for a spell that may have a minor impact on the game.  It's going to be fairly situational, but you could have some good moments.

Plot Twist Rating 3(Average): It's a cheap replacement effect, but it's a coin toss to RNG.  You're definitely not guaranteed to get anything better and you may even get the same cards back.

Vendetta Rating 2(Good): I think it's good as is, but if you manage to get it for free, then it's great!

Acornbearer Rating 3(Average): I think getting 4/3 worth of combined stats for three mana is typical, so it's nothing amazing.

Marked Shot Rating 1(Excellent): I think the 4 damage is fine, but getting to Discover a spell along with it is astounding!

Archmage Vargoth Rating 3(Average): I think he gets bumped up in ranking if you have a spell-heavy deck.  He's large enough to survive a turn or two and could give some amazing value, especially with stuff like Arcane Intellect.

Lucentbark Rating 3(Average):  He's a fairly large wall, but you really got to be able to wake him from his dormant state to take full advantage of him.  This is another clear indication they really want Druid players to start healing themselves.

Tak Nozwhisker Rating 4(Poor): It probably won't have consistent opportunities to copy cards in Arena and is otherwise just going to be a slightly overcosted minion most of the time.

Big Bad Archmage Rating 3(Average): It's really expensive, but you can get some great value out of it once you've ran out of options.

Call to Adventure Rating 4(Poor): This just doesn't feel good to me.  You may not be able to cast it right away unless you're mid-late game and by then it might not matter.  I think I'll just stick with Blessing of Kings, thanks.

Desperate Measures Rating 3(Average): Typically, Paladin Secrets aren't amazing, but the Twinspell makes this fairly decent overall.

Underbelly Fence Rating 3(Average): It definitely goes up in ranking if you have several cards that allow you to "burgle" your opponent's cards, but otherwise it makes a fine two-drop.

Aranasi Broodmother Rating 3(Average): It's a decent-sized minion with Taunt and heals are always welcome in Warlock.

Archivist Elysiana Rating 4(Poor): This just seems like a bad idea.  You can Discover some absolute garbage, so I think I would stick with the deck I drafted in the first place.

Hench-Clan Hag Rating 1(Excellent): You get 5/5 worth of combined stats for only 4 mana!  Sign me up!

Dimensional Ripper Rating 4(Poor): There is a good chance you blow your entire turn getting a couple of mediocre minions.  It doesn't seem worth it to me.

Shimmerfly Rating 3(Average): It's like the brother for Jeweled Macaw and it has the potential to give you something really good.  On its own it's fine as a one-drop, especially with the Beast tag.

Barista Lynchen Rating 3(Average): You can certainly get some great value from this, but it's just going to depend on the board state.  I think she's okay if you play her with no effect and although she's slightly overcosted the stats are still good.

The Boom Reaver Rating 3(Average): Even if you roll low you'll probably end up around 9/12 worth of combined stats - which is nothing to ignore.  I'm concerned about how slow it is and that RNG needs to be in your favor to have an immediate impact.

Conjurer's Calling Rating 1(Excellent):  You can use this on a minion that's about to die and get some amazing value and then use it again because of Twinspell!

Exotic Mountseller Rating 3(Average): It's slow, but it's got decent stats and nice ability if you've got the spells to support it.  It will really depend on your draft if you decide to include this minion.

Scargil Rating 3(Average):  It's probably not going to be very useful in Arena, but a 4/4 body for four mana will do just fine.

Arcane Fletcher Rating 4(Poor): You might have a couple of 1-cost minions, but this is situational, at best.

Azerite Elemental Rating 4(Poor): If you could protect it for several turns it could be crazy in the right deck, but slow and lackluster the rest of the time.

Darkest Hour Rating 4(Poor): It's another bid to RNG that you'll never want to use unless you've got a board full of tokens or just desperately outmatched on the board.

Jumbo Imp Rating 2(Good): Warlock has no shortage of Demons and I wouldn't be surprised to see this make an appearance in the mid-game on a regular basis.

Magic Carpet Rating 4(Poor): I don't know that it's unplayable, but it's pretty trashy unless you've got a very specific type of deck.

Portal Overfiend Rating 3(Average): When compared to [Hearthstone Card (Faldorei Strider) Not Found] it seems sorta meh, but I still think it has decent stats and the Rush ability on the minions could come in handy.

Waggle Pick Rating 2(Good): It's a good-sized Weapon and you get a (discounted) minion back from the Deathrattle.  Not a bad deal!

Whirlwind Tempest Rating 4(Poor): It could be a great surprise finisher if you've already got a Windfury minion on the board.

Witch's Brew Rating 4(Poor): Healing is usually not high on the consideration part for Arena decks, but I can see this being super frustrating when your opponent heals himself for 20 Health in the late game.  It's possibly more obnoxious than Healing Rain.

Arcane Watcher Rating 5(Terrible): I don't think I'll be drafting this any time soon.  It's pretty awful for Arena.

Convincing Infiltrator Rating 2(Good): This is going to be really annoying when facing Priest because you'll want to avoid it, but you can't because of the Taunt.

Hunting Party Rating 5(Terrible): This is going to be too expensive/situational for an Arena deck.

Impferno Rating 2(Good): It will be situational whether or not it buffs anything for you, but the 1 damage only hits your opponent's minions, so that's worth something.

Kirin Tor Tricaster Rating 3(Average): Giving yourself more expensive spells is not what you want to see in a card.  However, having +3 Spell Damage could be devastating for your opponent.

Mad Summoner Rating 4(Poor): It goes so nicely with Impferno, but unlikely to happen often enough to draft it.

Mysterious Blade Rating 3(Average): I think it's fine on its own, but really shines if you have a Secret on the board.

Portal Keeper Rating 3(Average):  The effect is identical to Portal Overfiend, but the cost and stats are different.  It's unlikely to survive long since it only has 2 Health, but the Rush minions still count for something.

Recurring Villain Rating 4(Poor): It could be mildly interesting in the right deck, but I think I'll pass.

Sunreaver Warmage Rating 3(Average): Depending on your deck, this could be awesome and would definitely go up in value if you're spell-heavy.

Sweeping Strikes Rating 3(Average): This could be absolutely devastating, especially if your opponent is dug in behind a Taunt.  It won't always be amazing because you've got to have a decent minion to throw it on to start with.

Tunnel Blaster Rating 3(Average): It might come in handy if you're playing from behind, but otherwise it's going to blow up your side of the board too.

Underbelly Angler Rating 3(Average): It's fine as a regular two-drop, but in the right deck this easily moves up in ranking as it will generate a ton of additional minions.

Underbelly Ooze Rating 4(Poor): It's probably too slow for Arena but can certainly get out of hand in the right deck.

Arcane Servant Rating 3(Average): It's nothing special, but at least it has an Elemental tag.

Blessing of the Ancients Rating 3(Average): It could be really nice mid-game with the Twinspell aspect.

Burly Shovelfist Rating 2(Good): It's expensive, but the Rush ability with its size is nothing to ignore.

Dalaran Crusader Rating 2(Good): I can see this is going to be really annoying to deal with.

Dalaran Librarian Rating 3(Average): It's much more of a constructed card, but will be fine if played on curve as a regular 2-drop.

Daring Escape Rating 5(Terrible): It's not often you'll find a situation you want to return ONLY your minions to your hand in Arena.

Eccentric Scribe Rating 2(Good) You end up getting 10/8 of combined stats for only 6 mana which is awesome!  I'm reserving final judgment until we find out what the Vengeful Scrolls that get summoned do.

Faceless Rager Rating 3(Average): It's good to see Ragers getting some more love and it's about as good as you would expect it to be.  Although, it could be a real problem in the mid-late game once you start putting larger minions on the board.

Flight Master Rating 1(Excellent): I generally don't like giving my opponent anything, but you're getting 5/6 worth of combined stats for only 3 mana.  That is amazing!  If you're able to take care of the 2/2 your opponent gets without trading in your own 2/2, then you've gained a huge advantage.

Hench-Clan Shadequill Rating 2(Good): This goes back to the Zombie Chow mentality, but since it's more expensive it's not nearly as amazing.  Looking at Chillwind Yeti sort of puts it in perspective.

Heroic Innkeeper Rating 3(Average): You need at least 2 other minions already on the board to make it worth it.  That shouldn't be hard to do, but if you aren't able to buff it, then it's going to be a real disappointment.

Magic Dart Frog Rating 3(Average): It's like Flamewaker's baby brother.

Mana Reservoir Rating 5(Terrible):  It's only a threat if you've got the spells to support it.

Mutate Rating 3(Average): It's like the discount version of Unstable Evolution.

Potion Vendor Rating 3(Average): The effect is nice, but the minion is so small it will difficult to really be happy when you've drawn it.

Proud Defender Rating 3(Average): It can be pretty good if you've got an empty board, but it's awkward to keep out there.

Rapid Fire Rating 3(Average): It's nice to get a small ping with Twinspell.  It could come in handy.

Safeguard Rating 3(Average): I feel sorta 'meh' about this, but I really think it's going to be awfully annoying considering your opponent has to waste 10 damage to get through the wall.

Soul of the Murloc Rating 3(Average): It's like a cheaper, less threatening version of Soul of the Forest.

Spellbook Binder Rating 3(Average): It's still fine as a 2-drop even if you don't get to draw an extra card.

Sunreaver Spy Rating 3(Average): It's another one of those that's alright as a 2-drop, but gets better if you meet the special condition.

Toxfin Rating 4(Poor): This will really depend on your draft, but most of the time I would pass.

Unsleeping Soul Rating 4(Poor): This is only going to be useful in certain situations.  The Silence effect just absolutely kills it.

Ursatron Rating 3(Average): It's nice if you can get the Deathrattle bonus, but even so, it's fine as a normal 3-drop.

Vicious Scraphound Rating 3(Average): I can see these little guys gaining ridiculous amounts of Armor if they're hid behind a Taunt.  Otherwise, they should be pretty easy to deal with.

Violet Spellsword Rating 4(Poor):  It's really going to depend on your draft as to how consistent this minion is.

Violet Warden Rating 2(Good): It's a large, reasonably-priced Taunt with Spell Damage.  That's some hefty power-creep on Archmage and I'll take it!

Just wanted to point out that the initial post has some incorrect info...Arena will *not* include GvG and will include MSoG.