In 10% of games, gremlins are capable of stealing intrinsics regardless of whether it’s night. This prevents you from classifying them as chaff that is unworthy of your attention.

Alternatively, do this for 10% of gremlins in any game, not 10% of games.

Gremlins generated not via cloning an existing one may spawn with a cursed scroll of light, and read it to create darkness when in the presence of brilliant light (Sunsword or gold dragon armor) or just randomly in lit areas when they sense an approaching player.

Archons’ light radius should be a passive aura area-of-effect attack that causes strong light effects: potentially blinding normal monsters, hurting gremlins and undead, petrifying trolls, and so on.

Assuming a monster intrinsics implementation: When a gremlin steals an intrinsic, it gains that intrinsic (if monsters having that intrinsic is coded).

Merge Sunsword and Trollsbane like NetHack Fourk does (a single artifact that emits light, instakills gremlins and instapetrifies trolls, with bonuses to undead), except keep it a morning star and name it Sunflash (because a lot of these consolidated effects have nothing to do with trolls). Having it stay a morning star makes it an attractive choice for Priests, and raises the appeal of training morning star.

When a gremlin steals an intrinsic from you, you can recover the intrinsic by killing it or eating its corpse.