First of all: Thank you for the awesome update!
Here are my thoughts on Grendels abilities and how you should improve them:
His 1: Consumes way too much energy. It is also hard to feast enemies when you're not aiming perfectly at the enemy and the enemies are already dead before I can suck them in my belly, because enemies get killed very quickly in this game.
His 2: Is hard to use, because you can't distinguish between his buffs. (It's a lot worse than Titanias 2). A selection like Ivaras 2 or Vaubans 2 would be a perfect fit.
His 3: The damage is very, very, very low for a third ability and doesn't even stagger the enemies. Also there seems to be no crowd control at all (no toxic explosion radius or anything). All in all, very boring and underwhelming ability imo.
His 4: Is suuuuper clunky and very slow in a game where super fast movement is everything. I'm also sad that you removed the possibility to feast enemies while rolling.