This card is balanced, but some people would say it needs a bit more of a nerf.
So i'm going to say what some person is likely to say.
That it should only do damage to all creatures, NOT destroy them all.
This is mass CC and mass CC needs a mass NERF.
Hm. In response to that kind of comment, here's what I would say:
Compare Rain of Fire which costs 7 | 5 instead but usually deals enough damage to wipe most of the enemy board, and Pandemonium that hits both sides for 3
with usually enough harmful effects to also wipe most creatures. This is more expensive than either so I feel the stronger destruction effect should be given the benefit of a doubt.
Also note that the damage/heal effect is intended to punish you the more advantage your opponent has - for example, if your opponent has 5 more creatures than you, using Genocide would level the board but also take a quarter of of your health away from you. That's way less efficient than Rain of Fire/Pandemonium in general.
