I am not so sure about how good this card is as it cannot be played on 3 mana, and on turn 4 or 5 this will be your whole turn. I think it is a good tool for zoo decks but not enough to carry the archetype and beat current control and cube warlock decks
This card feels like a worse version of the dragon Paladin card from Karazhan for an archetype that can use tokens better. I just don't see it being good enough though. It basically has to be comboed to be good which is bad for zoo. On top of that, you can't really play it on turn 3 when its body would be most effective. This feels like the weakest of the three.
Nightbane Templar didn't see any play - it was a 3-mana 2/3 with a comparable conditional battlecry. Control Warlock won't run Duskbat, and unlike Templar the new card isn't playable on curve, which probably means that it won't see play in Zoo. On turn 4, you might play this after Kobold Librarian, or Flame Imp, but it remains a dead card otherwise. The card doesn't impact the board when played - in the past, Zoo has typically only run conditional minions like Dark Iron Dwarf, or Defender of Argus which have a very low opportunity cost, and which immediately impact the board. You have to wait a turn to do anything with the extra 1/1s which a successful Duskbat generates, and Zoo doesn't really win by waiting around trying to fulfil conditions which allow it to out-value its opponent in the long run . . .
Duskbat [/card] bad dust . You can play this card at turn 5 or turn 4 with coin or in a[card]genn greymane deck. at that time a 3 mana 2/4 with 2 1/1 is not good. more precisely playing a 2/4 at turn 4/5 is not good, 2 attack minion is not going to benefit much from the 4 health.