I mean, the big issue is that the original LN had ended with Raoul taking over hell, but then the manga got popular and the author returned to write more. They said in the latest novel's postscript that Veronica is their favorite character, and that they wanted to dwelve into her character and...
I'm glad they changed Manaria's reappearance, it feels more natural here than in LN where she returned in the last chapter as some sort of last minute asspull.
I didn't call it wrong, I called it cringe.
The only reason "second girls" are added in shounen romcoms is to sell more merch or because writers can't find any other way to progress the main characters' relationships, so what is even your point?