Dysfunctional - An Assassin's Guide to Reincarnating in Another World - Chapter 65 - 64 - Apprentice(Part 1)

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

This story is set during the end of the Sui Dynasty, a time where multiple powers struggled for supremacy and power.

My disciple, whom I raised and cherished with my whole heart…That same disciple has returned and is trying to kill me.“Before you fall, before you cease to be my idol, my hero, my sun, I will kill you with my own hands. For your honor!”Just wait for a while…I’ll bring you back to your senses.

【Explosive New Book】 At Thunder Sound Hall, the Great Saint fell! With the Life and Death God Talisman, he reversed time and space; the Monkey King, unyielding, returned against the heavens! All gods and Buddhas lost their colors, my fate is determined by me, not by the heavens! In this life, I, Old Sun, will make all the gods and Buddhas remember this name— I am, the Great Sage Equalling Heaven, Sun Wu Kong