Like Deadpool in the DC Universe. - Chapter 29: Slade

When he returned to the World of Martial Arts, the game was filled with blood and battles! Chen Kaixin had chased after the footsteps of the one emperor, two empresses, three princes, seven dukes, and thirteen aces for three years, but during the eve of the Sword Among Us tournament in Mount Hua, he was ambushed by evil bastards, and was killed so much that his level dropped to that of a newbie. He completely lost the chance to join the ranks of the powerful players in the game! In great disappointment, Kaixin quit the game and got drunk so that he could forget his sadness, but during that stormy night, Chen Kaixin found that he had actually dreamed for a total of three years, because when he woke up again, he woke up to three years ago, when he was still a student.

- 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.

Bai Qingqing, the disciple of the Divine Physician, with goodwill, treats the domineering Prince for blindness, only to render herself at the mercy of him. In the name of practicing medicine, the doctress makes him have spicy cuisine for every meal as revenge. Seeing him frown upon the food, sweat at the pungent dishes, she is merely stoked! Poor Qingqing is no villain material, she ends up having a soft spot for him. Her tender care for the Prince unknowingly reveals her biggest secret-her true identity. After the prince’s eyes are cured, he mobilizes the military with great fanfare to keep her around…

A boy born with the potential, so great that it threatend the world's powerhouses itself._____Born amidst chaos and tragedy, Azhrael, the son of the legendary Frost King and Celestial Witch, carries a burden no child should bear. Half of his soul was dormant into another world, while the other half was left sealed, hidden from the prying eyes of those who sought to destroy him.He was a child of immense potential—his very existence threatened gods and shook the balance of power in the world.However in the main story, Azhrael was only an “extra.” A mysterious beautiful boy with snow-white hair and dull grey eyes who exists in the shadow of others, bullied and beaten, unaware of the legacy he carries.That Is Until.