Steel Legion/Bioforge DariLux AU
So @definitelynotscott showed interest in the setting for my upcoming DariLux fanfic based on Darius' Bioforge and Lux's Steel Legion skin, and I'm happy to provide!
It's fairly simple, essentially everyone is born at a later point in the universes timeline when the Void has rapidly progressed in subduing most of Runeterra and forced unlikely allegiances seated in megacities. Piltover and Zaun have politically united as the megacity Metroica, and Demacia and Noxus have reluctantly formed Deus around the Immortal Bastion.
At the heart of their alliance is a conflict based on both sides scared of losing their own culture - Demacia because they were forced to 'move in' with Noxus, and Noxus because they feel invaded by the Demacians trying to make themselves at home and preserve their own traditions in foreign surroundings.
The Crownguards are traditionalists and raise their children the same way, and Lux and Garen deal differently with that. Garen does what he can to satisfy his parents' ambitions, especially in his career, but the mutual attraction between him and Katarina is definitely there, and it makes him struggle. I won't spoiler too much beyond here! ;>
Lux has that certain freedom of being the younger sibling, and of course her curiosity and sneakiness help her walk her own path despite the morals she's being raised on (although the family atmosphere isn't particularly warm). Those start to be tested by the infatuation of her best friend Ezreal (native to Metroica, but doing a sort of exchange student thing) with their physical instructor at the Steel Legion, Taric.
On the Steel Legion, in a way it's the elite defense force for any sort of foreign issues, primarily against the Void, of course, but they're also present at any diplomatic events between Deus and other alliances as well as major inner political ones. The regular inner political affairs are managed by the police, which at times work very closely with the Steel Legion, which is Garen's place of employment. His parents chose it for him as a way of utilizing his strengths for political influence, but hardly respect the Legion in its own rights (as it is too inclusive, ergo Noxian), and thus were initially against Lux joining it, but couldn't really stop her from doing it anyway.
Darius is a Bioforged, a supersoldier augmented through Zaunite technology, back when that was still a thing. The technology grants their users superhuman strength and durability via an artificial second blood system, including a pump like a second heart, filled with something called 'elixir': that green stuff in the splash art. Unfortunately, it evaporates a little as long as the Bioforged is alive, but is vital to their basic bodily functions. That's one of the reasons the technology was forbidden (ethical concerns were uttered and laws seen through especially ex-Demacian politicians), and as a result of that, the official production of elixir was stopped. Darius, once high ranking in the Noxian military, now operates as an undercover wild card of Swain's among other elite Bioforge and is supplied with elixir, for the time being.
I hope that does it as much as setting! Turned out more complicated than I thought, haha... But yeah I hope it got you a little hyped and that I can live up to the stuff I've imagined up until now! Thank you for asking ~