Morangias said:
Sorcerer, because I have this hilarious mental image of indirectly causing havoc in the Empire while leaving calling cards with a trollface reading "PROBLEM, INQUISITOR?".
Would you also ask the Plague Marine "You jelly?"
But seriously CSM Sorcerer of Slaanesh or Tzeentch, depending on how I'm feeling, for somewhere between Warhammer Fantasy's Champion of Tzeentch Melee/Caster badassery and the more subversive Slaanesh feel.
Might be a fun way to play a high fellowship psyker.