Is it possible this metal worked is a PH for a named like the overseer, prophet and the Sorceror?
we killed him 3 times the other night - no ore in any form - just the normal acrylia runes. One thing of note however - this guy is not on the same 10 - 12 minute spawn timer the rest of the grims are on. His spawn rate is closer to 2 to 3 minutes for some reason.
Also I am reasonably sure he is at least level 40 as he was conning blue to me at 54
Serano