Youkoso Jitsuryoku Shijou Shugi no Kyoushitsu e - Volume 17, Chapter 1: Price of Victory, Part 2

A good-for-nothing man married a beautiful girl but was kicked off the bed on the wedding night. Furiously, he wrote a bill of divorce and ran away.
He was schemed a car accident in which he nearly lost his life. However, it turned out to be a blessing. He swallowed the soul that passed through the outer world, thus obtained superb medical skills and martial arts.
Later on, with the silver needles and invincible martial arts, he embarked on the road of counterattacks and was committed to his great dreams.

- Description from Novelupdates

After rebirth, Long Xiaoyuan went into raptures because he was in poor health in his previous life. However, he suddenly found that his soul was in the body of a fatuous and self-indulgent emperor.

[sexual content and lemons warning]Warning: Sexual content, lemons, Comedy, MILFs, Genius Mc and his harem.Possessive MC, Large Harem, Capable Harem members, No Conscience towards men, Mc is a Chill guy until anything happens to his women.~×~×~×~×~×~×~×~×~×~×~×~×~Ethan Nocturne always thought he was just a regular guy in a world where everyone awakens superpowers at 18. But when his birthday comes, everything changes. His body feels stronger, his senses sharper, and women—especially the ones around him—start acting strangely, drawn to him in ways he doesn’t understand.Then, the truth hits him—he’s not human. He carries the Incubus Bloodline, the rare male counterpart to a succubus. And his adoptive family? They’re not just powerful superhumans. His stepmother, Lilith Nocturne, is the Succubus Queen, and his three stunning stepsisters are Succubus Princesses—rulers of an entire fantasy planet.But here’s the strangest part—they don’t know what he really is.As Ethan struggles to make sense of his new reality, he learns that the world’s superpowers aren’t as simple as people believe. Fantasy creatures—elves, vampires, dragonkin, and more—aren’t just myths. They’re real. And they’ve been living in secret among humans.Now, they’re appearing in his life, drawn to him for reasons he can’t explain. His bloodline, his awakening, and the system guiding him—it’s all connected to something much bigger.Why have these races stayed hidden for so long? What is the real truth behind superpowers? And why does he feel like his very existence is meant to change everything?With a system pushing him toward his incubus instincts, powerful women from all over the world—and beyond—falling into his orbit, and forces in the shadows watching his every move, Ethan has two choices—fight it or embrace it.But one thing is clear—his life will never be the same again.

An Individual from Earth finds themselves in the Shinobi World, equipped with a Scientific System. From that moment, he delved into scientific research far ahead of its time.