Djinn

Djinn (ジン jin, Jin in the English Anime) is a genie and the guardian ghost of Mohamed Tabarsi.

About
According to Mohamed, Djinn is a magic spirit that will fulfil it's master wish, no matter what.

O.S. Mystic Beam
Mohammad's spirit is Djinn, a Genie that can successfully perform any wish asked of him. He uses it in a glass medium in his hand that fires a beam.

Anime/Manga Difference
Djinn is never seen in the anime.