Which Plane of Oblivion will he/she go to? Will he/she serve Sithis for eternity? Will he/she become the 10th Divine?

She will go to Valhalla and-Oh, wrong game.

She'll go to the deleted save box and become one with the deleted data.

Okay okay I'll stop joking. TBH Idk where she'll go. After the daedric princes have a war over her soul..who knows.

Sovngarde.

Since the dragon born is considered to be an avatar... of a god. Back to being part of that god I'd wager

Depends on which Dragonborn.

Since my Imperial is the one I primarily associate with the MQ, and since he rejected the TG and DB quests, he's pretty easy. He'll head for Sovngarde: though Imperial by birth, he's Dragonborn, which qualifies him for Sovngarde. Ditto with by Nord, by virtue of her race and her honorable nature. My Redguard will probably wind up in his people's equivalent of the same.

Most of my other characters, not so sure. My Dunmer's done enough daedric quests that a few of the princes might have a claim on her, and my Breton's dabbling in Conjuration makes him questionable as well, even though he mostly deals in flaming familiars and ash spawn. My Khajiit shuns daedric quests, but he's a vampire. I know werewolves get taken to Hircine's realm, not sure what happens to bloodsvckers.

To a table at Studio 54 where she will be forced to listen to disco music for the rest of eternity. It will be her punishment for ruthlessly killing so many bandits and wildlife.

You monster!

Hmm, i'm not sure, my Dragonborn is effectively immortal.

Back into the Hist.

ha well Sovngarde is very similar to Valhalla...they're both great halls for worthy warriors to get drunk and feast for all eternity, just trade a boar for a roasted cow

A Nord Dragonborn makes the most sense and Sovngarde is the most worthy retirement home for them imo.

If I had an Elder Scrolls after life, I don't know. I love kitties. As long as my family could come with me I'd go to a Khajit after life.

same place as most of the other Shezarrines