Tate no Yuusha no Nariagari - Chapter 224 - Fiancé

Lassen, a young man who has failed at everything in his life, has had enough. Disillusioned with the world, he decides to end it all. But instead of dying, he wakes up in a parallel world, armed with a strange system that can accomplish anything he desires. Trapped in his room, reading novels and savoring every page, he has no intention of participating in the fast-paced world outside.Yet, despite his desire for peace, the world changes every time he makes an appearance. Everyone treats him like a genius, a being capable of disrupting the very fabric of reality, without lifting a finger. A powerful system, a new life, and a world that adapts to him: why complicate things when you can have everything without effort?The Genius System tells the story of a man who, although having everything to change the world, prefers to watch it evolve from the comfort of his room, through the pages of his books.

A cell that was born at the beginning of the life of a planet will see the rise and decline of countless civilizations, the speciation and extinction of organisms. Under the endless calamities of the world, nothing remains unchanging. Only by continuously changing oneself and evolving in the face of adversity could one achieve perfect victory.

The story starts from a little cell…

- Description from Novelupdates

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.

A back-to-basics(?) monster evolution novel.