Rakish Little Immortal Doctor - Chapter 24: Missing Someone to Scrub My Back!

Lyle Walt is a young noble boy and heir looking forward to the day he can inherit his family’s territory. Except around when he was 10 year old, his parents started neglecting him more and more in favour of his little sister, Celes.
On his fifteenth birthday, he is challenged to a duel by his sister to see who will inherit the household and horribly loses, being cast out of his family. Afterwards, he gets treated by the family groundskeepers and receives the family heirloom Gem from him that Lyle’s grandfather had entrusted to him. From there, he begins an aimless journey with his childhood friend and former fiancée, Novem, and the Gem-turned-Jewel that houses the memories, personalities, and Skills of seven of his ancestors.

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

In the age of the Great Liang Dynasty, the lives of the people were made convenient with steam-powered machines that run on a fuel named Violetstream Gold. Chang Geng, who lived in a small countryside village, shared a distant relationship with his mother while his stepfather was away most of the year round, and the only people he was close to were two little kids, the village teacher, and his yi fu – adoptive father. But his life was flipped upside down one day following the barbaric Man tribes’ invasion, and it turned out that his entire identity had been an illusion – not only was Chang Geng himself not the country boy he thought he was, but also his mother, his teacher, and even his beloved yi fu…

- Description from Novelupdates

“Now you see?” she shouted in a mix of annoyance and disappointment. “You can't outsmart Scrients! They're the most intelligent beings across the two realms.”“You're right,” I muttered, averting my gaze with a heavy sigh. “I made a mistake. I was too arrogant to think that a mere human like me could fool them.”—BOOM!!“Heik! Wh-What was that?”“Hmm? I'm not sure. Maybe you should go and ask the most intelligent beings across the two realms. Oh wait, you can't. I killed them all.”______My name is Samael Kaizer Theosbane.On the last day of high school, I got into a fight with a kid I used to bully.It was a stupid, pointless scuffle, and in the middle of it, I tripped and hit my head on a rock.That’s when the memories came flooding in - the memories of another life, of a different world.Suddenly, everything made a twisted kind of sense. I realized two things.First, I was in a game I used to play in my past life.Second, I was a villain. A villain!Not the cool and mysterious kind, either.No, my destiny was to be manipulated and die a dog's death!I was the worst type of cliché: an ungrateful, privileged, insufferable young master. The sort you'd find in those poorly written fantasy stories.The kind everyone hates — a snobby brat from a powerful noble family who thinks he owns the world just because he was born with a silver spoon lodged in his mouth.You know the type. The one the hero beats to a pulp to prove his worth.Yeah, I was that guy.And the hero? The hero was the kid I’d been bullying all this time. The same one I got into a fight with.He was the supposed savior of this damned world.A world teetering on the edge of destruction, beset by wars, calamities, and a grim future that only I knew.And at the end of it all, the final antagonist of the game, the undefeatable boss… the Spirit King, was waiting.But could I even make it to the end?Could I conquer a game where defeat was the only certainty?A game that was now my reality!“Ah, fuck it.”I had no idea if I could, but I sure as hell was going to try.Extorting extras, manipulating main characters, twisting the story to my advantage, stealing the hero’s cheat items, killing villains before they could become threats - nothing was beneath me.Would the main characters be affected? Who cares!Would the story change? Even better!All I cared about was me—my survival, my life, my choices.“I will live this life with no regrets.”…But as I soon discovered, fate was not easily changed.And the price of altering one's destiny was steep.