Ezekiel is a spirit.

Spoilers here!
He is a type 3 Ghost; old, intelligent, and powerful. He displayed his capabilities by flinging objects with a flick of a finger. How much power and knowledge he had are not clearly measured or stated.

His apparition is described as having a golden glow.

He is the one who Marissa Fittes spoke to. He gave Marissa Fittes knowledge and understanding on ghosts, ectoplasm, seeming immortality, and many more that was only implied. His motivations and background were not explored.