Crypt Ghast

Crypt ghasts are the sentinels of the Orzhov tombs. These tombs house those who died in debt to the orzhov and there Ghasts make sure that noonecan use necromancy to reattack a debtors ghost to their body after death. They attack anny intruders mercilessly and uses the deathmasks of the surrounding dead as a means of channeling their attacks. Their attacks vary greatly based on what kind of person the mask belongs to and makes the Ghast a wildly unpredicatble specter.

For an instance: a mask of a former choleric could create a beam of heat, or the mask of a mentally sick person could create an effect that confuses the target.

Refferences:

https://scryfall.com/card/gtc/61/crypt-ghast