Yarok can act as a solid defense if your opponents get a little bold with their attacks and want to try and keep you in check with their creatures
In Commander, being able to determine lethal damage through power rather than toughness is a decent ability for Gruul
One other point to mention is that if you have a spell like Lightning Axe, which has an additional cost stapled to the main effect of the spell then you need to pay that cost even if youre casting for free
Ive been somewhat unhappily keeping Damnation around in my Vintage Cube, and I intend to try this swap there
Omarthis, Ghostfire Initiate Omarthis, Ghostfire Initiate works great in a colorless +1/+1 counter strategy, pairing well with modular creatures and Eldrazi Spawn tokens
Blue, however, would prefer to slow down and study the situation in order to find the correct solution