I remembered that the male MC was the senior brother in his sect, and due to jealousy that his master accepted a new disciple [the protagonist], he bullied him and all those.. in the end he died. So i think its either he reincarnated/someone transmigrated and he found out actually that he was a character in a book. So during the time the [transmigrated protagonist] was overcoming the sect entrance exam, MC saved a girl who was friends with the [protagonist] and then it started a 'butterfly effect' of some sort. Also the male MC's master didn't accept the [protagonist] as his disciple, making the [transmigrated protagonist] think it was weird because the book said he got to the master's disciple and also suspected that the girl that the MC saved was supposed to die as the book wrote and thought the girl changed some things hat was originally written in the book. Okayyy, i think maybe it was bl?? or it wasn't..
The Villian Has Something To Say https://www.novelupdates.com/series/the-villain-has-something-to-say/
sounds a bit like that manhua big brother has a pit in the brain or something like that "There's a Pit in My Senior Martial Brother's Brain" or maybe not