And, if indeed Tamriel is in a deadric realm without a daedric prince (Lorkhan?), then this is possible, though doing so may require more research. Perphaps, in doing so, the mortals of Tamriel could usher in "the dominion of mortals" (cf. the Dominion of Man in LOTR).
Talos took over the Mantle of Lorkhan/Shor. If (like Mankar Camoran alludes to in Oblivion) the Divines are nothing more than glorified Daedric Princes, then Lorkhan/Shor/Talos is the Deity of this realm.That is an interesting idea. Aside from Magnus, Talos would be the only godlike spirit who has all of its powers and remains interested in the plane or planet of Nirn. (Maybe the Thalmor figured this out and, in horror of this realization, now rage against the idea of Talos’s deification and mankind in general.)
Technically, no godlike spirit which was involved in the creation of Nirn could take over whatever mantle of lordship which Lorkhan was creating, except maybe Magnus. This is because, under Lorkhan’s plan, the mantle of Nirn which Lorkhan was creating was intended for a godlike spirit which fully retained its divinelike powers, namely Lorkhan himself. As such, any godlike spirits which were involved in the creation of Nirn to some degree would fall under this mantle of leadership because they would be relatively weaker compared to the one who held the mantle of Nirn.
Having said that, my point in the comment which you quoted was that as long as mortals reside outside of the direct governing power of the standard daedric princes, namely the type of power which they have over their own respective planes of Oblivion, then it is very likely that the standard daedric princes do not have all-powerful influence over Nirn and its inhabitants.
... no Daedra, even Princes, can ever be killed.
To stifle argument revolving around the Daedric realms for each Prince, they used much less of "themselves" in the creation of their Realms, therefore even if you "defeat" a daedric Prince, they never die. They just get chucked into the Waters of Oblivion to be reborn again at a later time.
Even so, perhaps the standard daedric princes themselves could be
selectively and
completely shut out of Nirn somehow. http://www.gamesas.com/topic/1410807-so-which-daedric-prince-is-probably-the-least-hazardous-to-your-well-being/page__view__findpost__p__21533955, more research on this subject matter is needed.