You know... I can see how these annoying little shits totally misunderstood munchkins could make a fabulous addition as NPCs in a dungeon of doom, where their "(ahem) Incorruptible nature" and "inability to NOT steal things" has caused a perfect storm, where they have stolen a VERY SHINY thing, that also happens to be a conduit of unholy evil, placed there explicitly to "deal with them", by the gods of chaos and evil. (Let's say that the object projects into nearby sentient's minds the raw essence of pain and suffering-- causing vivid hallucinations that are never the same twice, but are always of the most horrific grimdark shit, that is incomprehensibly traumatic, intended to incite mortal races to the greatest feats of unspeakable evil. Kinda the ultimate evil motivational poster, but with added bonuses to goal achievement when carried.)
EG, the balance of the world is indeed maintained by having the munchkins suffer incomprehensibly from their "borrowing" this object, since ONLY THEY can permanently endure its influence without becoming unholy abominations. They need to be insufferably plucky, while languishing in the bowels of the dungeon of doom.
Oh, and the evil sorcerer just happens to be using the "processed" evil that magically fails to corrupt the little shits to sustain his unholy presence in the world (Let's say he draws power from their nightmares after they keep subjecting themselves to this object's influence), and is not actually enslaving them; No no no.. They are totally free and can leave whenever they want, they just dont, because he makes all kinds of neat things that they can pilfer "borrow", and the idea of releasing evil into the world is terrifying to them-- so they have a literal case of stockholm syndrome about the evil castle of terror that was constructed around their horrible munchkin village, and the horrifying arch-lich that built it. That and the novelty of the object is infinite (because it never shows the same thing twice)