#au plot headcanons

Inspired by @eks-art

It started with Vanitas. In Braig's defense, he's pretty sure it isn't kidnapping if the kid's being abused.

Because Braig kidnapped surprise adopted Vanitas, he and Ventus never fight and form the X-Blade

However, Eraqus still dies, Terra still gets possessed, and Aqua still falls into The Realm of Darkness

Therefore Braig brings Ventus home, because he can't leave a child without a home

Vanitas misreads the situation and assumes he's being replaced as Braig's adoptee apprentice, and runs away ("You brought Ventus here. Obviously it's because you want to replace me with him! Ventus is the one everyone loves! I'm just the unwanted dark half!" "Kid, that is untrue, and I'm starting to think I should invest in getting you therapy. You are not unwanted.")

Then Subject X (aka Skuld) gets found

Braig sees Subject X, sighs, goes home after his shift, explains to Ventus and Vanitas that he's going to bring another another kid there and that he's not replacing either of them ("That was one time!"), and then kidnaps surprise adopts Skuld

So much Union Cross related angst

Ventus, Vanitas, and Skuld get worried when, one day, Braig doesn't come home

He returns in two days and explains the whole "Xigbar situation"

Then Radiant Gardens falls to darkness (becoming Hollow Bastion). Xigbar sort of parents them while the three of them are living in Twilight Town

Kh 1 happens and Xigbar has to check on his (now 26 year old) sons charges (and he checks on Skuld, too) when he sees Roxas, only to find them with Sora ("WHEN DID YOU HAVE A KID?!" "I DIDN'T HAVE A KID!")

Anyway, Sora, Roxas, and Xion have been kidnapped adopted into the family

Then Sora's memories get nuked by Naminé and Roxas and Xion go poof. The loss of Roxas hurts everyone, and Xion going forgotten leaves an impact, since this found family weird friend group always feels like someone is missing

Imagine the protests when Sora (and Riku and Kairi, although they haven't been kidnapped adopted into the family. Yet.) Has to go home

Just. Dream Drop Distance's whole premise being something that Yen Sid is shouted at for ("YOU SENT TWO CHILDREN INTO SLEEPING WORLDS?! TO MAKE THEM KEYBLADE MASTERS!? TO FIGHT IN A SECOND KEYBLADE WAR?!")

Xehanort finding (and subsequently trying to recruit) Vanitas

Xigbar betrays Xehanort when Xehanort tried to get him to hurt one of his children during The Final Battle(s)