probably easy answer, Does it take a divine being to banish a daedra back into oblivion or could a mortal with Divine weapons and such manage it?

Well considering Pelinal Whitestrake did it to Umaril with the Crusader armour i would say a mortal can do it.

Umaril is an elf though

A mortal can do it, especially a mortal that knows their proto and neonymics (basically an incantation specific to each daedra that will drain their essence back to Oblivion)...

Reference the http://www.imperial-library.info/tsobs/part06.shtml

technically an Ayleid

but yes I think the mortal needs some sort of incantation

Pelinal Whitestrake was NOT a mortal man, and Umaril the Unfeathered wasn't fully Daedra.

No, it does not take a divine being to banish a daedroth. The process of banishing a daedric being is as follows:

"As written, the Daedra cannot be killed, but can only be banished back to Oblivion. In order to banish a Daedra, its mortal body must be destroyed. Sometimes, this is not an option since some of the Daedra are terribly powerful in arcane and martial arts. Some knowledgeable persons learn the existence of protonymic. By using this protonymic, one can banish the Daedra almost "effortless". The incantation of the protonymic drains the vital force from the Daedra, forcing it to follow that force into Oblivion. There one abides until the vital force is replenished. The experience is somewhat anologous to sleep for mortals. However, sleep is a normal experience for mortals. It is not a normal experience for an immortal. Suffice it to say that it is as close to the terror and despair of death as an immortal can come. Naturally the banished Daedra will return to its Daedric Realm, however its personality is somehow changed, as well as its protonymic. Usually the protonymic is extended with neonymic; obviously this means that a Daedra cannot be banished with the same protonymic twice." (http://www.imperial-library.info/book_daedra/)


I hope this helps, for I remain...


___The Word Merchant of Julianos