I just don't like how specific it is. Flavor wise I just absolutely love it. But requiring you to target just a minion, deal only 3, and get a coin only if it dies, for a whopping 4 mana, just doesn't seem that usable. If you think of just the amount of mana it would cost if it dies as 3, paying 3 mana to deal 3 to a minion seems super weak when there's a card that does 2 damage to an undamaged one for 0. There's room for the card but it seems pretty slim. Again, maybe a Miracle deck could play this, I'm just pretty disappointed with this at Epic.
You know, in speculation, I think this is Blizzard making sure Rogue has a new coin in Standard that isn't too strong. Problem is, Hearthstone's expansion card pools are generally so small and restrictive for each class that classes getting prematurely nerfed cards means those classes will probably just be bad. I can see liking the card as support for a Wild miracle list, maybe as a one of. Preparation usually makes any card good but I can't help but see this as Backstab's ugly cousin.
so best case its a 3 mana deal 3 dmg to minion on turn 4 (3 if u use a coin for it) or 4 mana deal 3 dmg to minion in the worst case. I don't think its worth it for the potiential coin so meh not good but hopefully it isn't unplayable.
Blizzard should make a special stream lessons or youtube videos in which they explain the the only way hs should be played is with supa dupa 1000 IQ control/combo homebrewed decks and 30 minutes long match is a minimum time period that proves you're not braindead blah blah something etc.