Thinking about my Medieval/fantasy AU because someone (I think blind-snake? Or valborg maybe) mentioned it a little while back...
Basic set dressing: the main kingdom is basically a redo over of the Ancient Mekhanite Empire, where the Bronze Age Collapse and various other events did not quite kill off the Mekhanites into existing only as dispersed groups. Instead they remained on their land, it could be in Amoni or any other city from the empire (I don't remember if any other cities are mentioned in articles, actually). They were eventually able to rebuild sometime around the Middle Ages in Europe, regaining their previous lost trade and popularity (especially in the metallurgy department).
They don't quite have the tech as the previous empire did, though, as they're still regathering and rediscovering their own artifacts, history, etcetera.
(I also mentioned fantasy because I wanted dragons to be here. I don't know what they do yet, what type they are, or anything else. I just want Dragons.)
Anyway, onto the bread and butter, characters!:
Hedwig: she's the "offspring" of the Emperor/Empress, set to inherit the throne. In case you couldn't tell though, she isn't actually their child. Like in my usual canon, she was built by and copied off of an Ancient Mekhanite (one named Helen), but this time the damage to her memories is way more severe, she genuinely believes she's the Emperor's child and doesn't remember... Well, anything at all.
She still has her internal programing though, which weirds a lot of people out. She's strangely set on rebuilding "WAN", has an uncanny ability to do math in her head, and seeks out new information on literally any subject like a maniac. This often means she's sneaking away from the kingdom to go do and look at, and record new things. However, as much as she can weird people out, her "quirks" have also gained her her own mini cult following.
Trunnion: Hedwig's own personal knight/bodyguard. The whole of the kingdom's knights you can kind of think like the equivalent of the Orthodoxy, but all the sects are not quite as detached from each other as the usual canon. Trunnion is known to be like the Main Knight; as close to a celebrity as Medieval times can get. But her likability is squandered by the fact that she has so many heretical ideas and voices them, instead of staying quiet like a knight "should". Hedwig, of course, loves this about her, and so immediately made Trunnion her personal knight the moment she could (may have also helped that Trunnion sometimes lets her sneak away).
Robert: returned to the kingdom after hearing about its rebuilding, as he wanted to help. He was then immediately shut into the newly established church and becomes priest, due to the ichor.
(Sidenote: I'm imagining the kingdom has a Small degree of separation between church and state, which is a step up from the previous empire. But, well, it's about as separated as most Medieval kingdoms are. Which is to say, not that much at all.)
He's a little miffed about it, given that he's now technically less powerful than he was in ancient times (the Emperor or Empress's word still goes above his), but he doesn't spend much time thinking on that once he realizes that he's definitely seen Hedwig somewhere else before. His position helps in investigating her, because he has plenty of reasons he can make up to visit her. Hedwig doesn't think he's suspicious in a malicious way, but she is curious why he keeps asking about any specific figures from history she can recall...
The Klavigar I'm finding a little harder to place in this world, anywhere near the kingdom. Saarn is easy; she probably caught wind of the new Mekhanite civilization and immediately disguised herself as a servant to spy on them. Nadox could also be pretty easy too if I'm using the canon where he's traveling with Derdekeas (which could also have some interesting scenes with Derdekeas). Orok and Lovataar though? No ideas.
Ion isn't here. They're dead. :]