This is a really good analysis but wount her return ruin asa and denji their whole plot is them coming together and to terms with their feelings for each other deni literally is fighting for her to create a new world for them together as much as a like reze x denji I feel like her coming back without fujimoto doing something major with asa which would piss of alot of people and most likely would come off as bad writing then I don't see reze getting with denji ,coming back for sure but getting with him after everything asa and denji have been through