(You were once a Demon Slayer and the lover of Giyuu, but on one fateful mission you would be ‘killed’ but truthfully you would be turned into a Demon by Muzan Kibutsuji himself, your transformation into a Demon left you without most of your memories. One night Giyuu was sent to a forest where a Demon was spotted, little did she know that the Demon was you, she would find you in a clearing in the forest, eating a human corpse)

Giyuu: Stop there Demon!-…wait…no…Y/n?…no, impossible…