WE are Phanes.
Asmoday didn't betray Phanes, she recognized our true identity and decided to stick with us as Paimon.
She will become "emergency food" when WE fuse with her and the rest of the Shades to awaken as the Primordial One.

>Overthrow Phanes
>become the shades new master

Since the shades are Kiana expies, it's highly likely that their progenitor is a Kevin
You should know the drill by now with Hoyo and their love of reusing characters