Fire manipulation or some kind of shadow ability
His armor makes me think of rhino horns, so some kind horn growth power?
I don’t know why but I feel gravity manipulation whenever I look at that picture. I can just imagine him shooting off black holes at people.
Phasing with smoke manipulation?
Dark Fire manipulation
Grim Reaper Physiology with some death and dark powers thrown in? IDK, but he looks the part.
And darkness manipulation
What do you think?