A counter yes, but its not nice to have an auto-loss that your character caused, almost being worst than not having him in the team in the first place.
Vaders AoE is gonna need something to counteract the turn meter as his debuffs have turned from being a good to being a bad thing.
a) Make the debuffs more potent (like stun or ability block)
b)add another move that allows vaders move slot so that he can do something when either tenacity up is on board or if a character like admiral thrawn is on board and he isnt restricted to just his basic
c) not allow turn meter to be added during AoE