Infinite Mana In The Apocalypse - Chapter 3112 The Resurgence of Lumen! III

Van and his friend Magus had reincarnated in another world with magic. Tasked to kill the demon lord, they set forth.Van was granted very rough skills that made life for him in that world a living hell, yet he muscled through.Magus however, was bestowed with unfair skills. Due to some of said skills, he gained a harem, which in time, included the girlfriend Van made in the world.After beating the Demon Lord, and after finding out his girlfriend had been stolen from him, he got very upset and so he went to propose to... The Demon Lord...!?

As a man who had lived for 20 something years and had always considered himself as a straight man, he woke up one day and found himself possessed by a stupid and cute system. Moreover, it was a gong-shou cultivating system?! Let’s see how a shou with raised hackles evolves into a (pseudo)queen shou, incidentally with a story of a hidden loyal dog gong.

- Description from Novelupdates

Waking in a strange yet familiar room the main character now will rise to the top of one most dangerous worlds of fiction with his new cheat.