MTL - Tempting You to Marry Me—Pampered Cute Wifey - Chapter 837 You are my girlfriend now.

Sherlock is a new generation Dungeon Lord whose ambition is to become the greatest Devil King and building up the greatest Dungeon in the Underworld.

He summons a group of other-worldly goblins who give themselves strange names, form cliques, engage in commerce, and even fight among themselves.

They call themselves—Gamers!

- Description from Novelupdates

I had been abroad to do medical volunteer work, when I was swept up in a civil war. I was killed by a rebel soldier, while taking a bullet for a patient. But when I finally woke up, I had become a child?!?And in front of me stood a destroyed carriage and a group of oddly dressed people, who were unconscious!“It’s just like a Murim world.”As I hurry to perform first aid in an attempt to save even one person, I realize that this world is that of [The Supreme Demon King], a Wuxia novel I’ve enjoyed reading.After meeting the rescue team of the ‘Three Great Doctors’, I found out that one of the person I saved was the protagonist of this novel, the future Demon King ‘Yeo Haryun’!“Hey, since I’m indebted to you for saving me, call me ‘hyung’.”For saving his life, I become sworn brothers with the future Demon King, and the White Dragon Godly Doctor, one of the most knowledgeable people around, recognized my potential and took me in as his disciple. This is the story of how I became the greatest physician in Gangho!

He is a young man without a spirit root. It is believed that this denies him the chance at cultivation. However, a mysterious lady imparts a Supreme Demon Classic to him and from then on, he starts his path of cultivation.
He undergoes a total transformation to emerge as the most fearsome and powerful fiendish demon in his era, that even immortals and fiends are fearful of him, and saints are at his beck and call.
Mastering the Supreme Demon Classic is the turning point in his life. He is able to unleash his immense and divine power from within, illuminating the entire universe!

- Description from Novelupdates

A Hentai World is a Dangerous Place, Especially if Your Best Friend is a Hentai Protagonist and You Are a Trap.