playable only because of the amount of deathrattle support priest has, even then I dont think its that good.
Big decks will have responses to it and small decks will just ignore it (the outcome wont be great)
The power of this card is kind of bonkers. Not sure why you would view it as 'not that good' honestly.
The vanilla outcome for this effect is a 3 mana 2/3 summon a 2/1 with Harvest Golem. A more relevant comparison would be Snip Snap at a 3 mana 2/3 summon two 1/1s. However, Snip also has the magnetic, echo, mech thing going for it. This card is already better off as a 3 mana 3/3, which is already unprecedented for 3 mana cards with deathrattle summons. As for it's deathrattle summon, it's almost certain to get better value than a 2/1 or two 1/1s. I'm finding it hard to imagine how this isn't at the very least 'good' if not better. I mean, hell. In many situations, this card becomes a 3 mana 3/3, deathrattle summon a 2/3 deathrattle summon two 1/1s on curve. That's kinda insane.
Against small decks, this card helps you catch up on the board since it replaces itself. Against big decks, this is the type of card that makes your opponent waste answers they'd otherwise rather save for other threats. It also seems generically useful enough that it'll fit into all but the very niche priest deck (ie: Resurrect priest).
It'll be interesting to see whose right about it though. I mean, there's been so many cards that look great on paper that end up not making the cut and I freely admit, I may be missing the mark on this one. I'm just having a hard time envisioning this not being at least playable.
1
Just plain good in every Shaman deck except Murlocs.
2
Given this card exists and is the first revealed druid card, I'd say the chances of their being more hero atk buff cards is very high.