The magician may force an entity that is possessing a target to be expelled from it. The target of the spell is considered the target of the possession, not the entity itself. An additional energy requirement for this spell is to raise as much energy as the entity has Willpower. The entity may attempt to resist by making an opposed Willpower roll.
The entity will be locked out of the target for the duration of the spell. If, at the conclusion of the spell's duration, the entity has not been banished or the target protected in some way, the entity may return, and all his opposing rolls against exorcisms by that magician will be +1 cumulatively.