I Was Banished from Heaven, Now I'm the Demon King's Stepdad?! - Chapter 2 – “A Father’s First Firewall”

Finding himself in an Last Airbender without an airbender around, a transmigrator waterbender goes on an adventure to stop the worst from happening to him.

“God, please. If you are real, make my one last wish come true. Let me live.”When Callisto got diagnosed with an incurable genetic disorder at age 5, she was expected to live for only ten more years.With her life on its last leg, Callisto underwent an operation that has a one in a million chance of success called the Mutated DNA Fusion, granting her wish to live. However, the operation gave her more than what she wished for.With her black hair turned silver, cat ears overhead, and a tail from her behind, Callisto now has to live her life as a half-human and half-animal, a catgirl.

Master martial artists were beings that no one can obstruct. A martial arts expert has been reborn into the body of a genius whose cultivation has been abolished and has been abandoned by a woman. Therefore, he starts cultivating the art of Xing Yi Quan, producing a solar system within his dantian. His innate talent tramples over all the geniuses, and even the geniuses among geniuses.

His powerful spirit and ruthless and ambitious nature, no matter who he is reborn into, will never change! Slaughter is instinctive, being cold-blooded is his personality, exterminating an entire family is only a means towards a goal, cruelty means infamy, and chasing after women… is just an interest.

- Description from Novelupdates

A genius schemer, creating an emperor!

“Only when your brother is happy can you be happy.”

She committed all kinds of evil deeds to make him Emperor. However, Artezia’s devotion was repaid with betrayal. It was the Grand Duke Cedric, a righteous enemy, that gave her a hand of salvation at the threshold of death.

“Devise a plan.”
“…”
“I can’t think of anyone but you who can reverse this situation. Marquess Rosan.”
“…”
“Lend me your strength.”

There is no plan that can reverse the already declining power and save the fallen empire. However, there is a method. To turn back time before everything went wrong.

With tears of blood she sacrificed her body to an ancient magic. This time, she will not fall.

Artezia, who returned to the age of 18 before death, resolved to become a villainess for the Grand Duke Cedric.

“Please give me your hand in marriage. I’ll make you emperor.”

In exchange for kneeling to the devil, the devil shall dirty her hands for you.