Your thoughts on Vader's unique to make him viable?

Chaoscore

What if he restores 1% (maybe 2-3% on max level) health and protection for every dot present on enemies in the end of his turn.
So he is harder to kill early on with counters, but on his own, if he's like last man standing, still gonna be nuked by whole team focusing him, also as less enemies are alive, unique heals less, so it's less helpful in duel