Hello again! I'm back with a second idea after talking with my Star Wars buddy.
What if he got a buff everytime an ally dies or goes below half hp and for every buff he gets a damage bonus. Each buff would be unique if possible.
This would contrast Vader perfectly because on the dark side he uses debufs to deal massive damage (introverted power and capable on his own).
On the light side however it would take time to build up momentum, much like Rey. Since Jedi are about supporting each other and staying healthy, he would benefit greatly from their health fluctuations. Possibly he would lose the bonuses when his team is healthy.
TLDR a low hp team makes him a demon.