If a monster is both covetous and has the ability to break boulders, allow them to warp onto the same space as a boulder next to the hero if there is no free space to land, and destroy the boulder with a message like “[Mon] materializes in the same space as the boulder, shattering it to bits!”

Change covetous warping so it only works for demon lords on their lair levels, and then they can only warp back into their lair.

Covetous warpers can only warp to the location of the item they covet. This means that if you are carrying it, they can warp to you all they want, but they can’t warp back and forth to the stairs.

Covetous monsters can warp to the up stairs only if they know where the up stairs are. Demon lords would know this in their own lairs, but not otherwise, and monsters randomly spawned on a level may or may not.

Covetous warping only works on teleportable levels. It should also count as a regular teleport and cost Pw for the warping monster.