Max is a sinister self taught surgeon who is as smart as he is perverted. Max is one of the main figures in the "Sons of the truth" Cult and works as a simulation engineer, as well as a medic. Although his operations are rather unconventional, he is the last resort for ones rejected by traditional medical work, doing indulgent, often dangerous operations for the sake of realising the most twisted bodily fantasies.

As twisted as Max can sometimes be, he still craves comfort and hugs, symbolised by a soft sweater underneath his dirty lab coat.
And yes, the mechanical arm is his sick project as well, self inflicted harm to test out the waters.