Lord of Flames - Chapter 9: Divine Gift.

Outer Sect Disciple Chen Yu, assimilates within his body a fiendgod heart.

The heart, is the backbone of life, the human body’s fatal vital point. And it can be said that Chen Yu’s heart is actually his strongest defense point, and permits him to overtake demonic beasts, or divine beasts unlimited potential.

Henceforth, he steps onto the stage and surges forth on a magnificent scale, in a heart-rending mysterious journey.

Talented as a cloud, an unparalleled supreme talent.

10,000 races glorious, cross boundary battles.

Only my heart, eternal!

- Description from Novelupdates

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.

It was a dangerous era. Extraterritorial ferocious beasts occupied 90% of the living space in the world, while humans could only survive in a small space. Fortunately, some of the surviving humans awakened to genetic martial arts! Breaking the shackles of one’s genetics was the foundation of cultivating martial arts. Lin Feng, who was born with congenital disease, could not experience a breakthrough. However, by some fateful encounter, he awakened to the ability to merge genes.

Just as Li Meirong thought her life couldn't get any worse, she transmigrated into an abused body of a servant girl being sold at a brothel in a completely different world.