A Hentai System in the World of Danmachi - Chapter 213 - 212 - Takemikazuchi.

An accident gave Ye Han a magical ability to see through. Since then, his life has become rich and colorful. He has developed the strongest business empire, dominated the gambling world, and rejuvenated his medical skills. He has become a master of medicine and Taoism. The goddesses rushed towards him one after another. As a man, and a limited edition man, Ye Han was under a lot of pressure and had to go on an exploration with a few tomb robbers. However, a shocking secret from ancient times to the present gradually emerged. in front of him!

- Description from novelbuddy

This novel is also known as Transcendental Mechanic

What do you do when you wake up and find yourself inside the very game that you love?

What do you do when you realize you that you have not only become an NPC – you have even been thrown back in time to before the game even launched!

What will happen when our protagonist’s two realities coincide?

Han Xiao was a professional power leveler before his transmigration. Using his past life’s knowledge, Han Xiao sweeps through the universe as he prepares for the arrival of the players. This is definitely not your typical transmigration novel.

- Description from novelupdates

“I Possessed the Academy’s Silver-Rank Examiner.”I was on the verge of becoming someone who’d be pushed around by students left and right…◎ [Silver Gatekeeper]“No one can pass without the Gatekeeper’s permission.”I awakened an absurdly overpowered trait.TN: This novel follows a protagonist who becomes a rank examiner, tasked with evaluating students at an academy to determine whether they are worthy of advancing from Bronze to Silver rank. Known as the Silver Gatekeeper, he has the authority to decide which students can progress. As a gatekeeper, he possesses overpowered abilities, making him powerful when fighting on the examination field.

When Dirga signs a mysterious contract, his world is turned upside down. Shadows stretch, reality bends, and he’s thrown into a brutal game where power means survival — and the cost is everything.Guided by a devil with a smile too wide and a past too deep, Dirga must train body, mind, and soul in a realm where death is never far and every choice echoes beyond comprehension.Armed with evolving powers and a weapon tied to his very will, he steps into a world ruled by chaos, facing monsters, trials, and truths that were never meant to be uncovered.But in a game designed by devils, with rules no one fully understands — how far can conviction carry a man who fights not to conquer… but to protect?