Book elements: [Demon Slayer: Kimetsu no Yaiba fanfic / Sort of a sword / Healing / Really no NTR / The male protagonist is mentally unstable / Multiple worlds / Multiverse / Kitsune / Star Iron / Genshin Impact / Bears / Crayon Shin-chan / etc. / Funny in the early stage and be careful in the later stage / Tears are low and be careful /]
This novel has everything. What kind of son-in-law is there? Real or fake daughter? Real and fake young master? There are many themes.
