Shackled City 4e, YCS
Half-duergar, half-troll, heavily-armored slaver who led the Hobgoblins in the Malachite Fortress.
Kazmojen came from the Underdark several months before the beginning of the campaign and started up a slaving operation in the Malachite Fortress. In Episode 1, his agents had kidnapped the children from the Orphanage. The party tracked him down within the Malachite Fortress and confronted him; they bought the children and other prisoners back from him and forced him to leave Cauldron forever.
Since then, the party has never heard from or seen him.