The priest in the Live-Action version isn't actually a priest.
He fails his exorcism completely and the girl is still possessed at the end. This suggests that whatever kind of pretender he is, he is not a validly-ordained priest, and the real priest he passed by at the end of the video is forced to pick up the pieces. The girl who was possessed in the live-action Ghost was saved by the mage in the Magic animatic.
She killed her parents while possessed, and the beast took her soul into the underworld. Enter...a very flamboyant, pink Necromancer
; who raises the spirits of the peacefully departed who want everyone to share that peace, and eventually her parents. They raise the demon, and defeat it and purify the girl's soul; so she and her parents can Ascend to a Higher Plane of Existence.