Inside the Cave of Obscenity - Vol 3 Chapter 14: Saint 2

An average man is reincarnated in the world of DxD! How do you survive in a world of battle-hungry monsters? With a cheat skill, of course! Devour the competition, becoming stronger with every fight! From the depths of the Familiar Forest, the Beast King will rise. (Harem, Gamer!SI)

“Ding! Choose your idle skill.”“Ding! Idle complete. Language level +999.”“Ding! Choose your idle skill.”“Ding! Idle complete. Basketball level +999.”After a freak accident, Qi Ning acquires the “”Unlimited Idle”” system. But just as the system binds to him, it crashes, leaving a repair time of 999 years. However, to Qi Ning’s surprise, the system still allows him to idle, and with every second of idling, any chosen skill instantly reaches level 999.With his life now dramatically transformed, will Qi Ning’s rise from mediocrity be unstoppable?

Jun Ye travels through worlds for unexplained reasons and is always cast in subservient roles. Unfortunately, that wasn’t his style. Let the counterattack commence!

- Description from Novelupdates