ToME: the Tales of Maj'Eyal

Liches in vaults can summon shadows, which can pop outside the vault, even when you have not opened the vault. This is instadeath if you're in the shallow end of the Infinite Dungeon, and still pretty damned deadly even for characters in Dreadfell.

Similarly, the Withering Thing will summon shadows before you ever spot him. This is really problematic because you can be instakilled if you're weak but you can in turn scummily kill them (depleting the caster's resources) if you're strong. Given this, shadows probably should not chase stuff around out of their owner's LOS.