In the Second Generation of the Trench, He Changed To the Ruanfan Script - Chapter 3:

After an unexpected death, a soul finds itself reincarnated into the body of Itsuka Shido, an ordinary teenager in a world filled with powerful spirits, magic, and dangers from other dimensions. With the help of a mysterious system integrated into his body, Shido gains the ability to travel across worlds, summon legendary anime characters, and unlock a wide array of random skills and abilities.Disclaimer: The cover isn't mine, credits to the original artist.

Betrayed and used, Adam Palestar was a man that dedicated ten years of his life to reach the top in the game—Mortal Online—where the strong rule and weak are abused. It was a game where a single death meant the loss of all the hard work. In the end, he died in a way that was common in this game—betrayed by his closest companions—but he never expected that to happen to him.Now, reborn and regressed back to his younger self, he has a second chance—failure is not an option.

The unparalleled Demon King Ye Xuan, who was able to heal the death or the living alike and holder of the medicine Holy Scripture, was betrayed and killed by his fellow Demon Kings. But he reincarnated into the body of Ye Xuan, the prodigal son of the Ye family and vowed to himself that he would return to his peak and take back everything that belonged to him!

- Description from Novelupdates