Premise: Hater gets Isekai'ed to his most hated anime DxD, ( hates the pervert, the boobs, the stupidity of some characters, The harem etc)
What will he do Destroy Japan... Maybe, But that would make not Fun for readers, (Very tempting)
Maybe Murder the entire Casts, No again not Entertaining no the reader (Plot would Safe you, but not from me)
how about Cuck Issei does are popular for disgustingly some reason ( I would Commit Multiversal genocide but just by doing that)
(P.S Issei never meets Odin reason why his a pervert in the first place I think)
I don't know drop your ideas anywhere