possibly be a part of Nirn or a realm within Oblivion itself? I've been playing this game recently and it certainly feels like an Elder Scrolls game in more ways than one. I could actually see it being either....
1) An area of Nirn located somewhere in the distant sea. We know Tamriel is not the only continent and the rest of the world remains somewhat of a mystery.
2) A realm in Oblivion. Furthermore, the Void would be a Daedric Realm with the Outsider and god-like being before the Outsider being Daedric Princes. Obviously, the Outsider's Void is not the same as The Void mentioned in Elder Scrolls lore. Also, Dishonored Void is said to be like a sentient being itself so the Void is both a Daedric Realm and a Daedra (although that seems to be the case with all Daedric Realms anyhow).
3) Future Nirn is another possibility. I would certainly be much more exception of Dishonored being what happens to society in the future than the ideas brought forth in C0DA.
Were there ever any hints of Dishonored being in the cosmology, anyhow? I'm currently.... somewhere in the game after I rescued a certain person from a certain bathhouse. I'm digging in and interested in if those two franchises could reasonably cross over. Okay, I'll duck and dodge bullets now.