DxD: Scion of Lucifuge - Chapter 11: Two More Servants Acquired!

“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.

“I'm going out to do something, so I can't take care of you any more. You can go down the mountain and have fun. But if you can't find someone who matches your Innate Pure Yang Body in three years, you're finished!”These were the last words the old man, who was Lionel Yeager's teacher, threw to him before he vanished. Meanwhile, having mastered most of his master's skills, Lionel Yeager went down the mountain and took his first step into civilization for the first time in years.With his unparalleled medical and martial arts, he sets forth on a journey, befriending new allies and crushing all the enemies that stand in his way, as he attempts to resolve his Pure Innate Yang Body constitution, and cultivate to the top of the world!

An accident gave Ye Han a magical ability to see through. Since then, his life has become rich and colorful. He has developed the strongest business empire, dominated the gambling world, and rejuvenated his medical skills. He has become a master of medicine and Taoism. The goddesses rushed towards him one after another. As a man, and a limited edition man, Ye Han was under a lot of pressure and had to go on an exploration with a few tomb robbers. However, a shocking secret from ancient times to the present gradually emerged. in front of him!

- Description from novelbuddy

Allen, an eight-year-old boy from a poor family in the royal capital, is living a poor but happy life together with his mother. One day, however, memories of his previous life suddenly come back to him and he remembers that he is in an dating sim game and that the capital will be destroyed by war if he doesn’t do something about it. If this continues, both he and his mother will be killed! With a sense of urgency, he decides to rise to the occasion in order to save his precious mother’s life and save his favorite character, the villainous young lady Anastasia, the only girl he liked in the game, from her all too tragic and ruinous end. This is the story of a man who isn’t even a character in the game, but who strives with his steely determination and uses all the knowledge he has to turn overcome fate!