you play it, then free warleader. Seems decent but why you would want to play murlock right now? There is no incentive even with this included. It's an ok tempo card. Who knows, maybe we have more expensive murlocs coming. There is a new 5 mana one but that's not very good, the 6 mana board clear one could be strong with this and swing the board since it doesn't hit your stuff if you're playing all murlocs.
Seems like a fun card to me. I like that they're finally recognizing murloc warlock, the original murloc deck. Most of the murlocs are really cheap though and you can't justify putting a 4 mana 4/2 in your deck.
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If shaku had more attack I'd consider it, like it would be probably better at 3/2 even, it's not going to get you two cards ever anyway so that way it can actually kill things. In alt universe where Blizzard doesn't under stat every rogue card and treat like other classes, it would be a 3/4 with stealth!
The main kicker at this point is that everyone understands finally how strong a random card from a random class is and the answer is mediocre quite often.