Heavenly Divine Doctor: Abandoned Concubine - Chapter 29

A skilled but unfortunate modern-day assassin was killed in a freak accident. However, he soon found himself summoned to another world by an evil wizard, who had him possess the body of a boy as an experiment. After successfully planning the evil wizard’s downfall, he used the wizard’s body as a springboard to gain influence and power in his new world.

- Description from Novelupdates

When the average man is suddenly thrown into a video game as an extra, fated to die, they might first think to hide or run away. But not Luka. A man now inhabiting the body, he simply wants to survive - no matter the cost - even if it means he has to kill the main character!

Failing in his job hunting, Sanada Kyouichirou was hopeless in this society. When kyouichirou had thrown himself towards the bottom of a cliff. When he woke up his body had returned towards when he was in fifth grade of elementary school. He did not want to have any regrets in this life so he had decided on building up an harem in this second life.

The elder sister that he admired, a senior and president of the student council at a school for rich young girls, a strong minded upper classman at school. The poison fang of Kyouichirou who had pretended to be a innocent child attacks those girls.

An underachiever, a chance accident. He gained the premier Cultivation Technique, and from then on, his fate was completely changed.Cultivating superpowers, protecting the campus beauty! With overwhelming strength, he swept through all formidable enemies and made the world tremble with his military might!This is a tale of world conquest! It is also an unbeaten, fiery legend!