Are any published monsters in Dungeons and Dragons 5th edition described as stealing souls (or otherwise interacting with souls)?
From the Monster Manual:
- Demiliches are described as feeding souls to their phylacteries, but have no way to do so. Acererak-style demiliches devour souls.
- Night Hags trap souls in their Soul Bags.
- Liches feed souls to their phylacteries.
From Volo's Guide to Monsters:
- Barghests eat souls (along with the bodies they occupy).
- Devourers eat souls.
- Alhoons and Illithiliches (both varieties of mind flayer liches) feed souls to their phylacteries.