MTL - Immortal and Martial Dual Cultivation - v3 Chapter 2490 Buddha light annihilation

In a world of swords and magic, where Dragon Knights and Grand Archmages wield powers capable of destroying the heavens and shaking the seas, the legends of their prowess echo throughout the ages.In this world, Sylvus, having crossed over from another realm, opens the Eastern Elixir Shop with a unique system that grants him mastery over ancient elixirs.Within this humble shop, elixirs from the eternal archives of Xianxia are available—each more powerful and mysterious than the last.A Nine-Star Saint Archmage toils away in the shop, working to repay his debt.A Nine-Star Platinum Knight pleads with the shopkeeper, desperately hoping to buy just one elixir.Even God Mages and Divine Knights engage in fierce battles just to secure the coveted Nine-Transformation Golden Elixir before others.

Ryouma Takuma, a 39 year-old man with a hidden past, finds himself in a strange white room. There the gods tell him that he has died and that they are sending his soul to a different world; a world where magic exists. After living alone for three years his gamer soul loses common sense and starts toward crazy routes.

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

It was only after Su Yayan's death that she realized that she was a malicious cannon fodder female character who became a scapegoat in a Mary Sue story.