Caylis' And Lumine's Travels

Ships: Cyno x Tighnari and eventually Caylis (very slow-burn)
AU details: Caylis has Nico's demigod powers. Dainsleif is Caylis' biological (older) brother, Caylis was formerly dead just like Hazel was, but was given a chance to be revived, but inexplicably obtained Vidyadhara (HSR; basically dragon) horns and tail that she can hide by choice. Her appearance changed significantly upon entering Teyvat, as to not scare anyone, since she also was the Herscherr of the Abyss (non-canon, for OC lore) back at Earth.

Extra details: Book will start at beginning of Sumeru Archon Quest, but Caylis will have been traveling with Lumine since the start of Mondstadt. The Archon Quest order here is different from in-game. The order will be below these details. Caylis has gained anemo, geo, & electro so far and will gain Dendro, Hydro, Pyro, and Cryo just by entering the corresponding regions. Although, she rarely uses any. Lumine will be leaving Tighnari's hut sooner than Caylis does. Some characters will be out of character, but that's just for the story. Plus, Caylis' real name is Kienne.

Archon Quest Order in this book:
Mondstadt
Liyue
Inazuma
Fontaine
Sumeru (beginning of book, but Caylis has been through all Archon Quests with Lumine)
Interlude: Perilous Trail (the Chasm quest, begins sometime in the middle of Sumeru Act 3, and the book skips to next Nation to make it easier for me)
Natlan
Shadows Amidst Snowstorms Event Quest
Interlude: Mondstadt
Interlude: Natlan
Nod-Krai

Caylis full family:
Kiana Kaslana (yes, from HI3rd. They're twins, so Caylis' old appearance is similar to Kiana's.)
Dainsleif (older brother)
Welt Yang (from HSR and HI3rd, is Caylis' uncle on her mother, Myrah's side.)
Myrah (mother, deceased)
Hades (father, had to leave due to his duties back in the Underworld)
Adoptive mother & father (no names.)