Congratulations! You've been given the opportunity to create a brand new NPC for vanilla Skyrim, completely with vanilla bugs.
Who would this person be? How did they get to Skyrim? What are some funny things they might say in passing? Would they be a follower -- and if so, how would they fight? If not, why? and are they safe? Feel free to elaborate and answer unasked questions about this critter. (: This can be related to your fic(s) and/or existing OCs or completely separate just for fun.
Damn, that is SUCH a fun question. I was going to write about an existing OC I actually did make as a potential companion (my modding/writing collab and I have now accumulated a whole series of them based on GS, and set them loose in the game), however you said "complete with vanilla bugs," so... Paxius Duralius is a graduate student at the College of Winterhold, and immensely bitter at having his application to both the Synod and the College of Whispers rejected, despite his father's status as a prominent donor at both institutions (Paxius Senior did contribute a very hefty sum as a charitable gift to support the new alchemical laboratory expansion you might be familiar with if you use the Immersive College of Winterhold mod though, and that seems to have sealed the deal for Paxius Junior's acceptance). Now, it's not that Paxius is a bad student -- he isn't. He's perfectly mediocre: with average grades, average ideas (those mostly regurgitated from whatever popular opinion circulates in the more ritzy pseudo-intellectual salons of the Imperial City, though alas he has been in Skyrim for a few years now, and is a bit out of touch), an average pool of magicka, and no pronounced affinity for any particular school of magic whatsoever. Where Paxius does stand out, however, is in his linguistic pedantry. His tutors have taught him PROPER Cyrodilic and he won't let you, or anyone else, forget it.
Should you recruit Paxius as a companion, he will correct your speech, and that of anyone else he encounters. No being is too high or low for his interventions.
"Hear me and Obey!" says Meridia. "I truly think that 'Lo and Heed Me' would be much more appropriate, don't you agree?" says Paxius.
Etc. If you don't murder him by yeeting him off the Throat of the World, Paxius might have a quest for you to complete. It involves fetching his favorite socks from a dangerous Dwemer ruin. How the socks ended up there, or what makes the socks precious is never revealed. Paxius will get stuck somewhere midway through the dungeon because someone forgot to make the navmesh.
Paxius can be married, however since he is missing dialogues for the marriage faction tree, and isn't included in the Temple of Mara marriage scene, after the proposal he just wanders off and his alias eventually becomes disabled (we think it's on a timer, but we're not sure, his plugin crashes CK).
This is too fun an ask to not pass on, so @inquisition-dragonborn, @tallmatcha, @hogsbando, @friend-of-giants, @ktyxdovahkiin, @changelingsandothernonsense and any other TES mutuals who'd like to horse around (or not, totally ok to have a serious NPC in there too, I'm just in a ridiculous mood), consider yourself tagged.