teehee—⁠☆

Nyxaris isn't exactly a literal sacrificial bride, but the the Aesyrin (people of their homeworld) consider them as such because the primary Aeon that they worship is Fuli, but in this scenario; Nyxaris left their planet and rejected their beliefs in pursuit of following a foreign god: Akivili (the twins). As a result losing their place and memory in the planet itself. So it's as if they've never been born in Eidolon Vale and now cannot find nor step foot back there again, all in exchange for the gaze of another Aeon.

*So like sacrificial bride in a way where Nyxaris sacrificed their old self to stand next to her, inadvertently giving more reason for the twins to aid their planet

Upon first contact with the planet, Lumine expressed interest with Nyxaris and essentially stayed for a while to fix whatever issue the Eidolon Vale and it's people are facing. All while bothering a young and very rebellious Nyxaris, trying to convince them to join the nameless. Nyxaris eventually mellows out and agrees to take part on the twins journey, but since an Aesyrin's identity and physical form exists solely on Eidolon Vale, Lumine had to make sure that they could safely travel through space without vanishing into memory fragments. So she essentially binds a fragment of Trailblaze onto them to tie their existence onto the path itself, that way they can exist outside Fuli's gaze. Tethering their existence with hers as one of the embodiments of Trailblaze. So if you think about it it's like the exchanging of vows and an oath to be with the other for life (if you're delusional like me 🫡). This is the first lumine has expressed this much affection to another being other than her only kin, so the rest sort of recognize their relationship as an honorary marriage.

Their marriage is purely symbolic since it's not exactly a formal ceremony, but in Nyxaris' eyes they're a legally married couple lawl. But majority of nyxlumi is in nyxaris' perspective so who knows

Also also you are absolutely correct there, young/Pre-elation Nyxaris was stubborn and hid their feelings through acting tough (Tsundere biatch), Even after their marriage. They didn't think much of it at first, and only felt gratitude towards lumine. Nyxaris functions through obssesion, and the first object of that was the search for adventure, and they got that with Lumines help. As they settle in being a member of the nameless, their viewpoint of lumine as merely and Aeon that aided them slowly changed, and threaded the line of an almost cultish admiration. Pre-teyvat Lumine isn't exactly normal about them either so she was a-okay with the development.

In the peak of their relationship, Akivili mysteriously disappeared leaving Nyxaris and the rest of the nameless to carry on their journey. Nyxaris couldn't accept this and set out of their own to search for the Aeon in hopes of an answer, but eventually fell to their death after an encounter with Destruction (Nanook).

After their rebirth (thanks to aha), their perception and the mental exhaustion of their death twists their perspective on the twins disappearance, leading them to believe that they've been abandoned. Hence the obssesive quest to search for their wife, though now fueled with spite lmao

But the moment the find her in teyvat, now as the abyss princess, their obssesion shifts from finding akivili and getting answers, to dragging the now very confused and exhausted abyss lumine back to herself (even if they're angry about it the entire time)

HAHDGDHSGGSHS That's so messy I don't even want to know what'll happen 😭😭

I keep my venlumi and nyxlumi separate with AU's, and the only time both exist in the same scenario is if it's Abyss!Lumine. Lumine losing her identity/memory outside teyvat forming a relationship with venti (ex/situationship) and her actual wife suddenly appearing (technically also ex, since nyxaris is considered widowed after lumines apparent "death") is gwhdgdgsgg