From a Arena standpoint this is meta-defining. We have had cards like this in the past where it completely changes how players make decisions and adjust game play simply because that card exists, such as Fungalmancer, Mossy Horror in the past. Neferset Ritualist is one of those cards. Any injured minion or minion that can survive a trade is now a huge threat and potentially game ending if you or your opponent gets a solid hit on this effect. This card is absolutely terrifying. Every Arena game you play it will always be lingering at the back of your head.

It is a little disappointing but it's still decent enough that it will be added to any Reno Mage deck in Wild format. Unless there is more powerful no duplicate text cards coming it's not going to be a archetype powerful enough in Standard, but will be in Wild with more card variety and using previous Reno cards to fashion a solid deck. Basically the same with new Finley...Probably won't make the cut in Standard but is basically a auto include in any Wild Reno mage.