A Practical Guide to Evil - Chapter 48Vol 7 : Root

In the rebirth, in order to prevent the tragedy of the previous life from happening, Bai Yu decided to rush to the [Tower of God] at any cost, and face everything together with his sister!

However, Bai Yu, who was bound by the system, mutated his bloodline, and transformed into a black-scaled python seems to be developing on a completely different path from his previous life…

- Description from novelbuddy

The notorious imperial court lackey and the meritorious military general were well-known for their mutual dislike, a pair of arch-enemies set in stone. Who could have foreseen the unexpected change in the winds of heaven: the general injured on the battlefield, both legs disabled, and even forced by the emperor to marry his nemesis.  

With one marriage edict, two people with mutual hostility are forced to marry and live under the same roof. Yet after these long days together, they come to the realization that this fellow is not truly devoid of any saving grace/unattainable and high out of reach.

- Description from Novelupdates

In regards to the MMORPG Cross Reverie, Sakamoto Takuma boasted an overwhelming strength that was enough for him to be called the Demon King by the other players. One day, he gets summoned to another world with his appearance in the game. There, there are two people that insist “I am the real summon master.” Takuma gets slave-turning magic used for summoned beasts cast on him by the girls –

At 3 years of age, her father went missing. At 15, the muscle in her hand snapped. At 16, her mother passed away in a car accident. At 19, she was framed by her uncle. At 22, she was burned alive by her newly- wedded husband and her best friend. Perhaps it was God’s sympathy that allowed her to return to the time when she was 15 years old to re-live once more. The previous lifetime of being low- key and having forbearance resulted in betrayal and misery. In this lifetime, she must be lofty and domineering to let those who have bullied her suffer a terrible end!

- Description from Novelupdates