A Returner’s Magic Should Be Special (WN) - Chapter 97. Dungeon Attack (3)

Klaus had spent his entire existence as a puppet, bound by the strings of fate. However, a miraculous turn of events granted him a fresh start. The remnants of his former constraints smoldered in the ashes of his past. Now, unshackled and determined, he resolved to forge his destiny according to his own desires. No one, not even a deity, would be spared if they dared obstruct his path. Klaus was ready to wield the sword of vengeance and carve his own fate in the annals of history.

The world that nurtured the civilization which reached the pinnacle of magic was on the verge of destruction.
The last survivor transmigrated to the past, when the magic civilization started growing, as countless mages were still fumbling their ways through the thorny paths of magic knowledge.
He, who came from the end of the magic era, aim to reach the pinnacle of magic.

- Description from Novelupdates

Reincarnating into the world of Jujutsu Kaisen, he became Gojo Satoshi, the twin brother of the strongest sorcerer, Gojo Satoru. That should mean he’s destined to be the most powerful Jujutsu sorcerer, right?Unfortunately, fate had other plans. Nearly killed by Satoru in the womb, his cursed energy was devoured before he was even born. But at that moment, he awakened the [Shinigami Fusion System].Since he couldn’t become a Jujutsu sorcerer, he would forge a new path, a Shinigami with Heavenly Restriction!Thus, Gojo Satoshi, born without cursed energy yet possessing the legendary Six Eyes, became the true nemesis of Jujutsu sorcerers.

The former mercenary assassin Chen Tianlong has been asked to be the bodyguard and private doctor of Lin Wushuang, a pretty lady who is still a student. Their stories in the campus begin.“What's wrong, Tianlong?”“Your daughter is not sick, it's just that her Yin Qi is too heavy. The treatment for her is quite simple, find a man with abundant Yang Qi... and let him hold her while sleeping.”“This concerns Wushuang's life and death, and I definitely trust Tianlong, so let him try.”