This seems like a really weak version of devour to me... it may be useful with other fire cards i suppose, but compare it to oty...
unupped -
-this costs 2 more than oty
-this can damage creatures with higher HP than itself, but to kill such creatures, it would take ages.
-is worse at killing creatures with lower hp than it
-both get +1/+1 when they kill something
overall, unupped oty is quite a bit faster at killing stuff than this. Also, this costs a LOT more, because the cost is 2 higher to play, and the ability needs to be used many more times to kill stuff, costing more quanta.
upped versions, oty is so much better upped, so completely dominates this card upped... As I said earlier, this card may benefit from synergies within its own element, but other than that it seems underpowered.