I'm not so sold. If enrage only boosts skull damage, this trait might feel somewhat worthless due to random. Now if it enraged first ally, much better. But if enrage boosts spell damage too, then the trait might be good as is.
IMO, Doomclaw looks like he's just not good, too random. 25% chance for 2 devours is too low, but will be really awesome when it happens.
Infernus gets elemental shield LOL. But his two other traits look nice. I think I'm most excited for him.