There was a concept back a year ago for a fanfic of my dearly beloved oc x canon... I posted a chapter, and ended up deleting it because I was long gone from being active in the BSD fandom other than checking occasionally, and I had no idea how to place my character in a pre-set setting.
I posted the cover though,
It was meant to symbolize how Sigma could survive on his own even without his lover, but would forever be missing a piece if he did. On the contrary, Taifū couldn't survive without Sigma if he left, as without him, he is simply just a part of something floating around feebly without a destination or purpose. But it didn't quite line up with how the story was supposed to go.
Supposedly, both Sigma and Taifū had met and grown up together when they were young, and then both had their memories taken away by the book. Sigma was erased from all data centers, Taifū remained Taifū, atleast a hollow version of him... After they meet, Taifū slowly recalls memories—I don't know how, but trust me, because I'm the book/j—and eventually asks if Sigma remembers too. Sigma couldn't. Not a single thing. But even though he couldn't, he was fine with it, since it meant he'd be able to make new memories with the other.
That was the original concept..
Tldr; In my fanon au, Sigma is Taifū's whole, Taifū is Sigma's missing puzzle piece. He finds solace in the manager, and he finds a warm home with the assassin. Plot was amnesiac remembers and amnesiac 2 cant remember but loves amnesiac anyway
