Machina Arcanis: Two Worlds Collided - Chapter 6: Treasure Room II

Reborn in the immortal and demon world where righteousness and evil contend, Song Yan is kidnapped into the Puppet Demon Sect and assigned as a skin-making servant.During working, his system unexpectedly awakens, allowing him to enhance his lifespan and comprehension as long as he engages in skin making.[You absorbed the remaining life span of a stubborn donkey: 10 years][Please choose the lifespan to invest][You invested ten years of lifespan to comprehend Profound Root, you continued to lie there, being penetrated by ghosts...]

A Federation Colonel with abnormal thoughts was locked in a dark room and met a little looney.

“Your whole body emits a scent that I dread (covet) and fear (desire).”

A frigid Colonel X little looney roommate: A sweet story of interstellar travel

- Description from Novelupdates

Once through the pirates, Lu En became the son of Monkey d Dragon, a grandfather named Monkey d Karp, and an unreliable and neurotic younger brother named Luffy.

Fortunately, the ghost back system is activated!

The completion of the ghost back is 10%, and the training effect is increased by 100 times!

The completion of the ghost back is 20%, and the training effect is increased by 1000 times!

…

One day, Lu En, a ghost-backed master, appeared in front of Luffy who was shouting to go to sea, and made Luffy cry on the spot.

Luffy: “The pirates in the sea are all monsters like my brother? I don’t want to go out to sea!”

Garp: “For a long time, the two boys, Long and Luffy, with small arms and calves, I really doubt that they are not my sons and grandsons. Like Lu En, they are the grandsons of the old man!”

Warring States: “The strongest creature in the sea, land and air is Kaido? No, it’s Lu En!”

- Description from novelbuddy

The Bootlicking Antagonist Wants to Survive, but Female Lead refuses to follow the plotOne car accident and I’m transported into a city power fantasy as the villain. As long as I survive until the grand finale, I can return to the real world with hefty rewards. But! These stunning beauties don’t go to serve as the protagonist’s harem, they surround me every day. Are they not satisfied with how slowly I’m dying? Stop wearing stockings, stop wearing uniforms, what’s with all of you trying to seduce me? To find Long Aotian! Since destiny is in my hands, I might as well challenge the protagonist directly! Who’s the protagonist, damn it, who knows!