Overseers see over all realties. They are sumetimes called Overssers of all realitys and the physical laws that govern them.
They are able to freely traverse every corner of the Omniverse.
They are not Gods, but sometimes answer to Gods. They are not angels or demons, though they can be transfered in if they put in the proper request forms. They are immortal, invulnerable, and usually invincible. Incredibly resourceful cosmic beings with important jobs that keep the very functions of the universe in operation.
Correctors are responsible for ferreting out physical impossibilities and cosmic paradoxes before they unravel all of existence.
Such functionaries of the universe are either deceased spirits who are promoted, metaphysical golems created for the sole purpose of serving their Cosmic Lords and Ladies, or have always existed since the Big Bang don't question it.