One Piece: Capitalist Brook's Crew Expansion Plan - Chapter 1: Merging with Brook, Escaping from Hell

There is a turtle here,It's a bandit! A thief! A shameless scoundrel!Don't provoke him!~~~~~~~~~~~~~It doesn't belong to the orthodox realm of mythical creatures; it falls under the genre of Xuanhuan and Xianxia. I hope you all are aware of this.

It was a dangerous era. Extraterritorial ferocious beasts occupied 90% of the living space in the world, while humans could only survive in a small space. Fortunately, some of the surviving humans awakened to genetic martial arts! Breaking the shackles of one’s genetics was the foundation of cultivating martial arts. Lin Feng, who was born with congenital disease, could not experience a breakthrough. However, by some fateful encounter, he awakened to the ability to merge genes.

Yu Shanshan, who has been tyrannical and lawless for 20 years, suffered retribution at the age of 21. She changed from a little ballet princess of 45 kg to a poor and fat one of 90 kg.. Apparently, eating was the most important thing in her life. Her success in losing weight was far away.

However, one day, the father of her child who had disappeared for four years came back. From then on, Yu Shanshan was forced to embark on a diet that was worse than death.

- Description from Novelupdates

Xia Yan passed through to the world of Bleach and became an eleven-year-old boy. He was rescued by Renji and Rukia in the Seireitei, and he was studying at Shin’ō Academy, and he was a student of the same class.
He is a top student of the Shin’ō Academy, and he is vying for strength by various teams. In the end, he has entered the first team of secret mobile maneuvers.
He will use punishment to kill every person who tries to threaten the martyrdom and protect his loved one.

- Description from Novelupdates