He is Lovestruck in the Revenge - Chapter 239 - 232 Changling Takes Initiative Nasty Taste (First

Yun Xiangxiang was a well-regarded celebrity in her previous life.

Ludwig Heart, the heir to a vast fortune and a life of luxury, craves only one thing: freedom from his gilded cage. But when a plane crash catapults him into a world of magic and danger, he awakens not as the hero he dreamed of, but as a victim in a twisted ritual. Trapped between the ambitions of dark necromancers and the wrath of vengeful gods, Ludwig must navigate a deadly new reality where his life is no longer his own. Stripped of privilege and resurrected as an undead pawn, Ludwig’s fight for survival will determine whether he reclaims his destiny—or becomes a mere footnote in a world of shadows and deceit.

Transmigrated Become Sukuna, but the host is Yukinoshita Yukino?“Ryomen Sukuna? The strongest sorcerer in history? He’s just an ordinary person born in a time without me.”Hayashizaki stood in front of Ryomen Sukuna, looking at him with a playful expression.“On my left is the 'Little Yukinoshita,' a possessor of multiple techniques, easily wielding both the Limitless Cursed Technique and the Ten Shadows Technique; on my right is the 'Big Yukinoshita,' who has awakened a unique modern technique, no less powerful than me. As for slashing techniques, those are just our basic attacks.”“So, tell me, how do you, Sukuna with 15 fingers, plan to deal with this?”Ryomen Sukuna stared at the black-haired young man in front of him, whose cursed energy was identical to his own, dumbfounded.

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