Asa being the war devil carries a billion different questions.
>Why Asa was referred to as a human?
>Why Asa isn't faceblind?
>Why Asa was raised by a human mother that looks just like her.
>Why people notice that scars appear in Asa's face when she fights devils?
>Devils grow up extremely quickly, why did Asa have a seemingly normal childhood attending school?
>Devils are naturally sadistic and violent, why Asa, the WAR devil never shown any violent/sadistic tendencies? even Nayuta had them, who raised Asa that managed to supress her nature?
>To add above, Asa would have slaughtered several people even as a child, if she did in an unseen flashback or something, why did she stop? why did she forget? and why isn't she deep in a PS vault because of that? can killing even be a deeply traumatizing experience for a devil?
>Denji ending up with the Horseman of War seems very random in contrast with him ending with a lonely human girl that mirrors him (Denji and Asa also could never have children if she is a devil).
>If they're secretly the same, why do they occupy separate hemispheres of Asa's brain? and what's up with the imagery of Asa getting her skull split in half?
>What does that even mean for the story going forward? now that Yoru isn't trying to kill Denji and her plan is a total fluke, conflict between Asa and Yoru is really weak, which diminishes the impact of such reveal.
Beyond forcing the story bend itself backwards and outright contradict itself at times, my greatest problem with FC is how Asa and Yoru's relationship is really underbaked for such a reveal to make sense, it feels like an asspull because instead of the story developing a proper complex relationship between them, they just orbit Denji instead, it has been that way since Falling.