Rebirth: The Universe's Hidden Heiress - Chapter 1: Enrollment

Bai Aoxue, the best mercenary in the 21st century, is accidentally sent back to the Chengxi Dynasty in Great Continent due to an explosion in her mission, and trapped in the first daughter of Prime Minister. After her rebirth, she is set up by her father to marry the 5th prince Jun Yeyan who wears a mask all day long.
In the face of bloodthirsty enemies, discord between brothers, collusion among courtiers and invasion of enemy state, can Bai and Jun resolve the crises? What will happen to their political marriage? How will the fierce battle for the throne end?
With many twists and turns, the book brings you to experience palace revolution, love and hatred thousands of years ago.

- Description from Novelupdates

Cui Heng was transmigrated to another world and the system told him that the new world he was in was a high-grade Xianxia world.

When Kim Seojin opened his eyes, he found himself three hundred years in the future.In the last three hundred years, humanity went through a lot of changes. Science had developed, cities became more modern, and space travel became a reality. But all of that came at a cost.The world had become a plaything of gods. Every year, humans were selected to represent their race in a devilish game, all for the entertainment of the gods.Kim Seojin was one of the thousand people selected in a timeline where he didn't belong.There was one more person. A Regressor burdened with the memories of countless failed timelines and the knowledge of the destruction to come, was also a part of the game…

“Look, I don’t need to be the strongest — I just need to be slightly stronger than the guy trying to kill me.”---Zayn Eldrake was nothing more than a nameless extra in the grand tale of summoned heroes — a disposable swordsman in the legendary Hero of Light’s party, fated to die in an early battle against the monsters of the Apocalypse.But when he awakens in this doomed body with memories of his past life, he refuses to meet the same pathetic end.He knows the story. He knows the heroes. He knows their strengths, their weaknesses… and most importantly, their women.With the power of [Devourer’s Pact], Zayn can consume the abilities of those he defeats, transforming himself into something far greater than a mere extra.Strength, magic, divine blessings — everything in this world is his for the taking. And if fate itself stands in his way? He’ll devour that too.