Hello! Curious to know if you've seen any AUs around where A/C don't meet/become close until after heaven and hell end the world and go to war? Thank you~
There is a search tag - Alternate Universe - Never met, although there aren't many fics in it just yet.
Not exactly a during-a-war-meeting, but this is what I was able to find:
A Handbook on Half Holy Hoodwinking [T], WIP (10/12 ch) by cassieoh
“Why the fuck,” Raphael says, voice as smooth as the linseed thick in the air, “do any of you think you have the right to hurt my betrothed?”
There’s a pause in which Aziraphale can distantly see the confusion passing between Gabriel and the others, but he can’t really process much past ‘betrothed’. It feels as if the entire universe has ground to a halt around them.
Aziraphale is to be executed post-Apocalypse, the only way his friend Raphael can think to stop it is to claim they're to be married (can't kill an Archangel's husband afterall). They arrange to have the wedding as soon as possible on a little island with great Holy power. Meanwhile, Crowley (having escaped his own post-apocalyptic execution) is hiding out from Hell in one of the only places where there's enough Holy energy to disguise him.
They might not have meet in Eden, but really what's 6000 years between adversaries?
(quite a lot, as it turns out)
The Long Way Around [M] by Kurikukun, reduntant_angel
Aziraphale and Crowley never meet in Eden and the pair go on through time believing that other is the enemy. With Armageddon quickly approaching, Crowley is sent on an important assignment: to kill the angel and retrieve the flaming sword.
Things go sideways, however, when Crowley is severely injured. As Aziraphale naively nurses the demon back to health, Crowley begins to wonder if he'll be able to go through with it after all...
The Way Home [E] by GiggleSnortBangDead
Aziraphale and Crowley meet in 1979 while working on a film adaptation of an Ezra Fell novel. Aziraphale just had another fight with Gabriel and is looking for something casual, even if it's with a human. Crowley is not a human, but Aziraphale doesn't know that. In Crowley's defense, he also doesn't know that Aziraphale's not a human.
Aziraphale and Crowley meet again in 2019 while working on a film adaptation of the same Ezra Fell novel.