Fighting your demons (SaneOba)

Sanemi remembered everything. The weight of their past lives pressed heavily on his mind-their world of demons, of bloodshed, and the bond he and Obanai had shared as comrades, best friends, both demon slayers, Hashira. He could still feel the pain of their final moments, the regret. The faces of those they lost haunted him, the sorrow and tragedy more vivid than ever.

But in this life, demons didn't exist. This life was different, or so he told himself. And though the memories still burned, Sanemi resolved to bury them deep. The others didn't remember their pasts, not Obanai, not anyone. And Sanemi had no intention of telling them. This time, he would protect the people he loved, no matter what. What harm could come, after all?

(So basically an au where Sanemi remembers his past life, heavily featuring Obanai and Genya.)

It has a lot of blah blah blah at first.