Seirei Tsukai no Blade Dance - Volume 16, Chapter 8 - The Crimson Princess Maiden

I, Lin Yun, with my exceptional aptitude, had thought that I would be trained as a key disciple, however...“The Demon Sect will never expect us to send such an excellent disciple undercover. Once you attain a high position within the Demon Sect, with our help both from within and without, why would we worry about the Demon Sect's destruction?”Three years later.“The Righteous Path will never expect us to send such a promising disciple undercover. Once you attain a high position within the Righteous Path, with our help both from within and without, why would we worry about the Righteous Path's destruction?”Lin Yun: I just want to quietly cultivate to immortality...

In her last life, she was miserable and ordinary. This time, she got into the fashion and was reborn in another world. She was still the same person… even with the same body and face. What was the point of reincarnation? A childhood companion? He always pulled her hair and made troubles for her? A handsome boy? The boy never looked at her and was 15 years older than her! A prestigious teacher? The teacher spent his days eating and drinking, coaxed, played tricks, and controlled others… Too scary and better run away? No no no, such a challenging life was bound to be wonderful! Now let me take you back to the 70s and live a fast life!

- Description from Novelupdates

Nero was an orphan boy who one day went to sleep like any other day in his apartment. However, what he did not know that the moment he slept, it would be his last day of life...Or at least that was how it should be.Nero's soul wandered between the worlds and ended up entering the body of a girl who was trapped in a human mutation laboratory. While the girl's soul was still alive, he hibernated inside her body.After so many tortures, the girl named “Zero” in the laboratory died. But, it didn't end there, when the girl died, something very strange happened, something took control of the girl's body and that same thing escaped the laboratory.It was when Nero what that was hibernating in the girl's body woke up and realized was completely naked. In addition, he realized that he turned her into a beautiful winged woman with white hair and some pink strands.

A s*ave boy, Ram, who assassinated an enemy commander to end a war.Jedrik, the great chieftain of the North.Demion, the prince of the South.Charlon, the duke’s daughter.The blood oath they forged plunges a seemingly ended war back into chaos.