The Demon Monarch System - Chapter 1 - The Boy Falling To Darkness (I)

A martial art expert from the Song dynasty lives like a Phoenix that can live again in another body after death. This time, he happened to take over the body of a Japanese high schooler who is also a victim of bullying and has a bit complicated family circumstances.

- Description from Novelupdates

Cassian Ven Dyke, the bastard son of a powerful ducal family, grew up in the slums of Veldora under the care of his father figure, sword master Russel. When Russel passed away, Cassian was left with only a silver necklace as his inheritance. After putting it on, Cassian was attacked by three psychotic thugs who tortured him in an attempt to steal the necklace. Refusing to give in, Cassian was ultimately stabbed through the heart with the very same necklace. Instead of dying, he mysteriously vanished as the necklace lodged itself in his heart. Just before disappearing, he heard an eerie message echo in his mind:[True mana detected. Origin: Human...][Human detected. Compatibility with system: Confirmed.]

“What I want, the Heavens shall not lack! ”

“Ride this, my beloved consort!” Instantly rewarded with a punch in his charming face. He looked hurt, “I just wanted you to try out the mythical beast mount!”