Spirits, Demons, and Ghosts.

Spirts and ghosts inhabit the arena and often participate. Most inhabitants of the arena hold the ability to see spirits and ghosts, due to constantly being around supernatural forces.

Ghosts and spirits abilities vary, so its hard to tell what powers a ghost wields, although a common power is possesion and psychic powers.

Demons are creatures who are from hell or those who have acquired demonic abilities. In Arena, demons are common, like almost every other creature.