>>281247087
Asa will very likely turn Yoru into a weapon, it's the perfect karmic ending for her. She spent the entirety of Part 2 claiming ownership over Asa's everything, her body, her belongings, her emotions and even the boy she likes (Denji), stands to reason that at the finale Asa would claim ownership over Yoru herself. We already saw how their powers rely entirely on perception, so all Asa needs to do is to gain confidence to believe Yoru as part of herself/believe herself to be Yoru/The War Devil.