For his old powers, he has a totally indestructible arm made of magic metal. So why not let him channel his powers through it so he can do things like
>Shoot lightning or godblasts from it Surfer/Galactus/Goku style
>fling his fist into the air and then fly
>punch the air and make portals
>absorb energy from other people into it, and then maybe punch people with glow-ey fist
>punch enchantments/ghosts/immaterial/ethereal/barriers etc
>summon storms with a wave of the hand

Basically make him Unworthy-O:God of Fist and Punching things

His new thing would be flying fist first into everyone.