"How about this, then. I'll have the Inquisitors spike me, so the materials don't need to spend time outside a body and nobody even slightly dangerous ever meets you. Then only the person who transfers them from me to you needs to know about your existence. It can be someone with no magic. You'd have your pick of trusting their promise of silence or of enforcing it but revealing your capabilities.

The secrecy problems all seem solvable, not to mention unimportant next to the ability to ignore orders."