Akame ga Kill: Starting with Dual Kamui - Chapter 114: Love Fighting, Killing, and You the Most

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 transmigrating into a beast world, Rong Mingshi discovered that the people of this world experienced widespread mania. For example, when their emotions were abnormally agitated, they would become destructive beasts. If their emotions were abnormally low, they would shrink into their young beast form.

Returning to the Mysterious Era features a boy who can time-travel back to the past using old relics. The twist? He’s stuck in the body of the relic’s owner.After a near-death experience, Cassius unlocks his ability to travel to the past in the body of Li Wei, a member of the Wind Elephant Sect. Li Wei was a coward who lived a life of regrets up until the day the entire Wind Elephant Sect was mu*dered. As Cassius relives Li Wei’s past, he makes different decisions to show Li Wei a different kind of future.By living out the ups and downs of Li Wei’s life, Cassius is introduced to the world of Covert Martial Arts, ties that run closer than blood, and supernatural forces. Crossing the line between the ordinary and supernatural, he realizes there’s no way back. New friends and enemies slowly integrate into his reality.Now, he must uncover the secrets of Covert Martial Arts and get stronger to survive.

"When will people understand.... I'm only half insane?"