HIII CAN ANYONE RECOMMEND SOME MANGAS SIMILAR TO "Brutal: Satsujin Kansatsukan no Kokuhaku"
Not sure what you actually mean, here are some gruesome mangas (with blood, murder and mind break topic)
https://www.mangago.me/read-manga/shin_ai_naru_boku_e_satsui_wo_komete/
https://www.mangago.me/read-manga/children_miura_miu/
https://www.mangago.me/read-manga/chi_no_wadachi/ (Doesn't have any murder or smtg, just mind breaking and traumatizing story)
WHERE'S THE WEDDING AAAAAAARRRGHHH WHAT GIVE MEEE