DxD: Scion of Lucifuge - Chapter 15: Finding Rika Minami

When he was categorised as an Omega at the age of 13, Rong Yi made a tiny little wish. In the future, he wanted to fall in love with a tall, handsome and elegant Alpha whom he could share a romantic love with, then build a blissful family with him and give birth to many cute babies together.

A few years later, he grew into a tall, handsome and elegant Omega and was passionately pursued by countless admirers of the same gender, while all Alphas backed away from him in face of his superiority.

This was not the life he wanted.

- Description from Novelupdates

Su Leyun, the legitimate daughter of the Hou family, was replaced by a peasant woman during a plague when she was still in her infancy.

After experiencing hardships in life for more than ten years, she finally returned to her parents, but she was plotted and framed at every turn. She was even looked down upon and treated coldly because she grew up in the countryside.

She originally thought that her sincerity would impress her husband and win him the gift of betrothal, but she didn’t know that he only married her for the sake of pretending to be a match.

After resurrecting her life, she vowed to make those who bullied her pay the price. She knew what it meant to be respected as a legitimate daughter!

- Description from novelbuddy

Hyde arrives in a doomed world with nothing but his body and fragmented knowledge of the future from a game he once played. He has no grand ambition—why try to save a world already destined to fall? Survival is enough.That is, until he discovers his sister is also transported into that world.However, only he hears the Melody of Nightingale and receives the power to survive.[You have established a connection with The Forgotten Hollow.]Awakening as a Resonant—an elite group with supernatural abilities—he is thrust into a conflict between two worlds. Armed with the authority of space and time, he vows to protect his powerless sister at all cost, even if he has to fight against the Mirage creatures, other Resonants, or even Gods themselves.

There is no master god, no system, no exchange, and some are just source codes that are fused in the mind to open up the world, not to be forced or suppressed, but to constantly go through in order to become powerful Look at my infinitely powerful source code …

- Description from uukanshu