This is Deiter Gerhardt, aka "Mentok the Mindtaker!"

Mentok is a primary antagonist in our first collection of adventures. He picked his nom de hack by looking through a list of mind-controlling supervillains from classical literature and chose Mentok because he didn't really understand the contemporary context of who Mentok the Mindtaker is.

I give great thanks to @jackgross@slrpnk.net for this fantastic portrait.