Biokinetic grafting 
Skin-shedding shape-shifting 
Hooks?

hyperhuman powerset focused around talking to, manifesting, and manipulating/commanding the dead would be in the setting. Maybe it's  a kind of HZE-driven dominion over Uber/Unterseele, through the 'higher' Einseele? He'd be able to talk to the deceased to glean info others can't (Uberseele), temporarily animate dead flesh and have it perform a simple single command (Unterseele), and probably something around witnessing or experiencing moments of death when interacting with still-fresh corpses.