you were a tsuguko (for whoever) and you were on a mission, you failed and you got turned into a demon right after you killed the demon itself, the hasira knew and captured you now you are being held dowm by Obanai and the others are discussing what to do with you while you continue to growl and scream

Sanemi: "we need to kill them! they could kill people!"

Giyu: "they could be like nezuko..."

Mitsury: "so sad they became a demon after they were on the verge of being a hashira!"