read until chapter 87
in the first timeline, when the protag wanted to train under the ML, the MC said that it's tradition that they don't allow a second disciple into their peak. only 1 master and 1 disciple. but when protag insisted, the MC shrug him off and accidentally harmed him a little. the wound actually isn't really a wound, but the protag made it like it was serious. then the master/ML came and brought protag back to the peak to nurse him back and then took him as a disciple. since then people around at the sect knew that MC isn't fond of protag. and through many mishaps and accidental collateral damage, in which the MC took no part in but still gets blamed for it (and he sometimes was clueless about it), MCs reputation declines until he gets framed for killing his fellow brothers (which was actually that scum protag's fault!)
so, in the second timeline, the MC doesn't get impatient and replies steadily again and again that their peak doesn't accept another disciple. and since he didn't swipe his arms (like the typical chinese scene when people turn around and they "hn! (disdaining noise)" and they swipe their arms so that the clothes flutter around and walk away? yeah, that action), the protag isn't harmed. when the ML arrives, the protag shouts out to him and pleads to him to accept him, ML ignores him. the protag then gets dragged into another peak in which he isn't popular at all.
cute moments, there are many, one of them that wasn't mentioned:
when the MC wanted to leave the peak again to do stuff, the ML didn't want to let him go. even asked many times and even ordered MC to not go (bc he is worried he will get injured again, which happens every time he leaves, lol)
when MC first rebirthed, he was currently slaying demons. suddenly a book fell from the sky and landed before him. that was the first book. then he gets volume 2 and 3 after some time. at volume 3 he finally knows that his master believed in him and didn't want him to die. in that book it said that ML ordered the protag to get MC "home" (their peak) and gave him his sword to show it to MC.
so MC is moved and then shows the book to ML. that's how they both found out that they are only characters in a story. but i didn't see that MC and ML confessed that they rebirthed. MC only asked some questions to how would have ML reacted if blabla happened (like in the book) and ML answered differently (while being very pale bc of im remembering stuff and didn't want to admit that he did just that in the previous timeline).
also funny:
one of the harem members of the protag falls in love with the MC and joins the sect just to see MC again. While the protag thought that she was here because of him >.>
and since the MC acts very normal and strict like a senior brother should be, the protag is kinda moved and thinks good things about him (but still evil and heartless enough to want to bring down the first BOSS aka the MC) bc he is bullied in his peak by another senior brother (by 4th senior brother, he's hilarious and comic relief in this story)
also: the demon king/friend is also in love with the MC (MC has NO clue). when the MC was kidnapped, both ML and he searched for him and arrived almost at the same time at the villain's lair. after killing the villain and freeing the MC, MC interacts with his friend and ML sees this. after friend leaves, ML mentioned that 3rd Senior sister and him (the friend) would make a good pairing. MC is flabbergasted and asks what they have in common. ML says: they both like to wear red clothes. MC: "...."
->ML was kinda jealous or at least subconsciously feeling that that friend is a threat, lol ^^