Who Let Him Cultivate Immortality - Chapter 6: Senior Brother Dai, You Must Stay Calm

A tree of 10,000 flowers, the world is the door.
The spells change a lot, but the hearts of the people are unchanged.

- Description from Uukanshu translation

[Reminder: Yuri, GL, Yandere, No NSFW, Only Wholesome Romance, Toxic Heroines, Slow Paced, Slow Romance, Slow Burn, Slow Harem.]“Damn it, why the hell am I the Villainess?”Petra, a human resources manager, just went through a painfully dumb breakup. To cope? She did what any sane woman would. Binge-read a guilty pleasure romance and smut novel series from her teenage years, only to realize that the heroines have brain-cell-deficiency.One way led to another, she wakes up as Verena D’Auvergne—a minor antagonist who turned out to be the ultimate villainess of the whole series after an incident. The very woman who stole all the love interests and died trying!“Forget the male leads, I have to make the heroines forgive me!”Can she, the ultimate villainess, capture the forgiveness of the very women she was meant to destroy? Or will the cursed System, and fate itself, force her to chase after love?

Eldraus was once a normal world , peaceful, beautiful and full of life, much like Earth.But everything changed when the Beast Mutation began.Animals started turning into terrifying monsters larger, stronger, and unnaturally violent. Kingdoms fell. Cities burned. Humanity was pushed to the edge of extinction.Then came the System, a mysterious power that awakened within humans, granting them abilities to fight back. Over time, the system became a part of everyday life. Every person now awakens with a System, ranked from the weakest gray to the legendary black and above.This is a world where strength rules, and the weak are left behind.Kaelen Maglor, son of a noble, awakens with a rare black support system. People mock him, expecting him to be a healer. But Kaelen has no intention of following their path. He chooses to walk his own.With danger rising and powerful enemies lurking, Kaelen enters a deadly academy that trains the next generation of fighters. There, he will uncover secrets, face deadly trials, and learn that the system that grants power... might also be hiding a terrifying truth.In a world where monsters roam and only the strong survive, Kaelen must prove that even support can become unstoppable.

In novels with a stud there is always a Senior Martial Brother like this:

In the early stages of the novel, his innate talent is high, his cultivation is good, his appearance is handsome, and he has an intelligent, cute younger Martial Sister as a fiancée.

In the middle stages of the novel, he is caught unprepared and defeated by a young disciple (the protagonist) in the sect who’s hardly remarkable at all. From then on, he falls from his godly altar and loses his brilliance. Even his young Martial Sister leaves him for someone else.

In the late stages of the novel, he continues to turn dark, going down the Demonic Path and becoming the major villainous boss. However, the protagonist still ruthlessly defeats him and his soul is eternally sealed.

Once Qin Mo opened his eyes, he discovered that he had become this Senior Martial Brother.

- Description from Novelupdates