A 2 mana 1/5 beast is already a very fair statline, and this is so easy to corrupt! A 5 health poisonous minion likely gets to trade for 2 cards. Be it 2 minions, a minion and a spell, or 2 spells. Not a lot of spells can deal 5 to a single minion at once. And if a spell does kill it at once, you're still pretty happy. Not sure what deck this would fit in though, most likely in highlander hunter
In a vacuum it's really good value for the cost, but in practicality it's too expensive for demon hunter and doesn't do what demon hunter likes to do. There is some token synergy of course, but this addition is probably not good enough
First of all, good job on this class design. I really like the ideas you've got going on here, and you've clearly thought about what your class should be in terms of weaknesses and strengths. There are a few potential issues I have seen though, but I can be very nitpicky. So don't pay too much attention to me rambling on about minor details, but I hope it will give you something to think about :P
Let's start with the core mechanics. I like the idea of Tactic, but there are a few instances where I'm not sure what the intended behaviour of it is. I'm assuming it works like an aura effect, meaning that the effect goes away when the minion with Tactic goes away. First of all, Pandaren General, which gives 1-Attack minions +1/+1. Historically speaking, Hearthstone does not look at the base stats of cards but at their buffed stats, meaning that the +1/+1 buff would mean the 1-Attack minions don't have 1 Attack anymore and should lose the buff. This is also the behaviour I am expecting from Goblin Strategist. When a minion has 2 Health left, it gains Taunt. Whenever it gets healed or damaged, it loses Taunt. But then again, you seem to have disproven that this is the way it works in a previous comment. Therefore I would advise rethinking how the mechanic works exactly, or reprashing certain cards/the tooltip
Regarding the Shado-Pan Agents, this I quite like. It is like the Paladin Silver Hand Recruit synergies, but executed in a different way. However, I think the issue in this lies in the generators. There are only 4 cards that generate, and I would say that 2 (maybe 3) of them are playable. I'll go over them one by one, but I think this is just not enough. Paladin has the Hero Power as a constant generator, which makes up for a lot. I'll go over your generators one by one. Shado-Pan Trainer; I believe this card is nice for arena, but not viable enough for ladder. The guaranteed 4/6 in stats isn't terrible, accompanied by an end of turn effect, makes it playable in theory. However, I believe that you want to do more than that on turn 5 as a swarming deck. Also, you can't combo anything with the Agent, as it comes into play after you end your turn. Send in the Troops; Man, this card is strong. It's almost a Force of Nature, but for only 3 mana! So much tempo. I don't think it's overpowered, but I'd play this card in almost any deck. Huojin Taskmaster; Again, strong card. Casual 5 Mana 6/7, of which 4 Attack is protected by 4 Health in Taunts. Again, not overpowered, but strong nonetheless. Finally, Reinforcements; I really don't like this card :/. Let's compare this to Shadowform. The first time you cast it, this is arguably a downgrade of your Hero Power, while Shadowform arguably gives you an upgrade. Dealing 2 damage to a minion is such a strong HP that you don't want to change it to a slightly better Paladin HP. The second time you draw/cast it, at least Shadowform gives you another slight upgrade. All this will do is refresh your HP, for 3 mana and a card! Reinforcements should be a (2) Cost card at most, like Dinomancy.
Now I'll go through the sets and comment on any outliers, starting with Basic. Wide Defense is an interesting card, but horrendously weak compared to Sunfury Protector. Sure, you can't usually target the two outside with her, but she does the job done of protecting something you want to protect just as well. My advice, add "Draw a card." to it. Windstrike is a card I am indifferent on. I get the idea of it being your classic 2 mana deal 3 card like Frostbolt, Lightning Bolt (/Rockbiter Weapon), Darkbomb, Wrath, Penance. The problem is that your Hero Power already does so much of that. Would you really want to pay a card for 1 extra damage? Normally I would say no. However, this is one of the few cards that directly deals damage to a minion. So perhaps you would run this as removal, but I'm very skeptical. Then there's Stock Up. I get that you want to introduce the concept of rarity in the Basic Set. However, if I recall correctly, every Basic class card is contained in a version of a Basic deck of that class with only other Basic cards. So I would advise swapping this with Epic Treasure. Also, tutoring in the evergreen set is dangerous and limits design space. It could be fine in this case, as Rare cards rarely break the game, but it its worth mentioning.
So far so good, let's see what Classic has in store. Well, I really like all Classic cards. They all seem to have the right balane for Classic. The most questionable card would be Earthmaster if you ask me, because it requires 3 friendly Taunt minions to become a Fen Creeper. I think you can bump it down to 4 Mana. There is one card that doesn't fit in in my opinion, and that is Pandaren Collector. According to you, Tactic "will grant bonusses to any minions on the board that fit the tactic." So does that mean that it triggers on itself? Does it trigger on minions that are already on the board? Compared to an aura effect of Give +1/+1, the effect Draw a Card just makes very little sense to me. I may be alone in this, but it really triggers me, and I think it could confuse other/new people as well.
Curse of Naxxramas. Man, I love Strength of Spirits. Such a cool card, I just wish it was real. It makes so much sense, especially for a class that goes wide. My compliments
Then GvG, not much to say about this set. I would like you to clarify if Smasher Droid hits a random enemy, or both enemies when it is played opposite of two enemy minions. Also, with reluctance I will say that Gear Up could be bumped down a Mana. It is just as powerful as Bloodlust, as both will be used as finishers.
Finally, Blackrock Mountain. Again, good job, these cards are well designed. Nothing else to say about them.
I hope these comments will help you with making the best class you can. Really excited to see what else you can come up with, as you've done a great job so far. Keep up the good work!
Decent card for cheating out ring matron. Big deck making restrictions though. Will see experimentation, but not good enough
Very solid card, but it lacks taunt or anything proactive. Still very decent minion and might still see some play
Might see play in C'Thun Rogue, otherwise this is probably too slow
Random spell of the same costs are probably not great, but still not bad for the player casting. This just doesn't disrupt enough
A lot better than nightmare amalgam, but still pretty filler. This will probably see play in every n'zoth deck, but not in any other.
12 damage is so much overkill. Pretty good removal for elemental mage, but I don't see that becoming a major deck. Kinda reminds me of Crowd Roaster
3 mana sprint. Very solid. Will see play
A 2 mana 1/5 beast is already a very fair statline, and this is so easy to corrupt! A 5 health poisonous minion likely gets to trade for 2 cards. Be it 2 minions, a minion and a spell, or 2 spells. Not a lot of spells can deal 5 to a single minion at once. And if a spell does kill it at once, you're still pretty happy. Not sure what deck this would fit in though, most likely in highlander hunter
In a vacuum it's really good value for the cost, but in practicality it's too expensive for demon hunter and doesn't do what demon hunter likes to do. There is some token synergy of course, but this addition is probably not good enough
VENGEANCE
First of all, good job on this class design. I really like the ideas you've got going on here, and you've clearly thought about what your class should be in terms of weaknesses and strengths. There are a few potential issues I have seen though, but I can be very nitpicky. So don't pay too much attention to me rambling on about minor details, but I hope it will give you something to think about :P
Let's start with the core mechanics. I like the idea of Tactic, but there are a few instances where I'm not sure what the intended behaviour of it is. I'm assuming it works like an aura effect, meaning that the effect goes away when the minion with Tactic goes away.
First of all, Pandaren General, which gives 1-Attack minions +1/+1. Historically speaking, Hearthstone does not look at the base stats of cards but at their buffed stats, meaning that the +1/+1 buff would mean the 1-Attack minions don't have 1 Attack anymore and should lose the buff. This is also the behaviour I am expecting from Goblin Strategist. When a minion has 2 Health left, it gains Taunt. Whenever it gets healed or damaged, it loses Taunt. But then again, you seem to have disproven that this is the way it works in a previous comment. Therefore I would advise rethinking how the mechanic works exactly, or reprashing certain cards/the tooltip
Regarding the Shado-Pan Agents, this I quite like. It is like the Paladin Silver Hand Recruit synergies, but executed in a different way. However, I think the issue in this lies in the generators. There are only 4 cards that generate, and I would say that 2 (maybe 3) of them are playable. I'll go over them one by one, but I think this is just not enough. Paladin has the Hero Power as a constant generator, which makes up for a lot. I'll go over your generators one by one.
Shado-Pan Trainer; I believe this card is nice for arena, but not viable enough for ladder. The guaranteed 4/6 in stats isn't terrible, accompanied by an end of turn effect, makes it playable in theory. However, I believe that you want to do more than that on turn 5 as a swarming deck. Also, you can't combo anything with the Agent, as it comes into play after you end your turn.
Send in the Troops; Man, this card is strong. It's almost a Force of Nature, but for only 3 mana! So much tempo. I don't think it's overpowered, but I'd play this card in almost any deck.
Huojin Taskmaster; Again, strong card. Casual 5 Mana 6/7, of which 4 Attack is protected by 4 Health in Taunts. Again, not overpowered, but strong nonetheless.
Finally, Reinforcements; I really don't like this card :/. Let's compare this to Shadowform. The first time you cast it, this is arguably a downgrade of your Hero Power, while Shadowform arguably gives you an upgrade. Dealing 2 damage to a minion is such a strong HP that you don't want to change it to a slightly better Paladin HP. The second time you draw/cast it, at least Shadowform gives you another slight upgrade. All this will do is refresh your HP, for 3 mana and a card! Reinforcements should be a (2) Cost card at most, like Dinomancy.
Now I'll go through the sets and comment on any outliers, starting with Basic.
Wide Defense is an interesting card, but horrendously weak compared to Sunfury Protector. Sure, you can't usually target the two outside with her, but she does the job done of protecting something you want to protect just as well. My advice, add "Draw a card." to it.
Windstrike is a card I am indifferent on. I get the idea of it being your classic 2 mana deal 3 card like Frostbolt, Lightning Bolt (/Rockbiter Weapon), Darkbomb, Wrath, Penance. The problem is that your Hero Power already does so much of that. Would you really want to pay a card for 1 extra damage? Normally I would say no. However, this is one of the few cards that directly deals damage to a minion. So perhaps you would run this as removal, but I'm very skeptical.
Then there's Stock Up. I get that you want to introduce the concept of rarity in the Basic Set. However, if I recall correctly, every Basic class card is contained in a version of a Basic deck of that class with only other Basic cards. So I would advise swapping this with Epic Treasure. Also, tutoring in the evergreen set is dangerous and limits design space. It could be fine in this case, as Rare cards rarely break the game, but it its worth mentioning.
So far so good, let's see what Classic has in store. Well, I really like all Classic cards. They all seem to have the right balane for Classic. The most questionable card would be Earthmaster if you ask me, because it requires 3 friendly Taunt minions to become a Fen Creeper. I think you can bump it down to 4 Mana.
There is one card that doesn't fit in in my opinion, and that is Pandaren Collector. According to you, Tactic "will grant bonusses to any minions on the board that fit the tactic." So does that mean that it triggers on itself? Does it trigger on minions that are already on the board? Compared to an aura effect of Give +1/+1, the effect Draw a Card just makes very little sense to me. I may be alone in this, but it really triggers me, and I think it could confuse other/new people as well.
Curse of Naxxramas. Man, I love Strength of Spirits. Such a cool card, I just wish it was real. It makes so much sense, especially for a class that goes wide. My compliments
Then GvG, not much to say about this set. I would like you to clarify if Smasher Droid hits a random enemy, or both enemies when it is played opposite of two enemy minions. Also, with reluctance I will say that Gear Up could be bumped down a Mana. It is just as powerful as Bloodlust, as both will be used as finishers.
Finally, Blackrock Mountain. Again, good job, these cards are well designed. Nothing else to say about them.
I hope these comments will help you with making the best class you can. Really excited to see what else you can come up with, as you've done a great job so far. Keep up the good work!