Demon Hunter (Teramachi Akeho) - Chapter 29

Zero, a 35-year-old mercenary, after being betrayed by one of his teammates who told his enemy about him. He chooses suicide so that he can kill his enemy and his traitor teammate. After that, he was reincarnated into the world of magic, in the body of an 18-year-old teenager with the same name as him. However, his body does not have mana or the talent for magic. But with the help of the cultivation system, he has unrivaled power in the world and has a harem of beautiful wives.

In the world of One Punch Man, the seventh S-class hero of the Hero Association, the King Engine King has obtained the super god skill system.

As long as you have reputation, you can extract the skills of the heavens and the world!

DNF’s extreme swordsmanship, the flames of fire in the god of death, the Tensei and Samsara in Hokage, the top three-color domineering in Pirates, the dragon slaying magic in Fairy Tail… Look at the system panel. For the 100 million prestige balance, KING took a discount and chose Stud. “Ding!”

- Description from novelbuddy

An AI calling itself Schema has assimilated earth into its system. As a consequence, everyone gained access to status screens, power-ups, and skills. This AI turned these concepts from fiction to fact. It's easy to become intoxicated with leveling up and becoming stronger. To some, it's too good to be true like living out a dream.

For Daniel, however, it's closer to a nightmare.

He's in a bit of a predicament. Cracks in our dimensional fabric have unleashed terrifying beasts from dark, abyssal places. Schema organizes these cracks into dungeons, giving the native species of the planet a chance to fight back. Daniel finds himself trapped in one of these dungeons. Not long after, he discovers there's only one way out.