One Piece: The Dragon Knight of the Grand Line - Chapter 69: The Duel of Thunder and Light — Karl vs. Kizaru

After an unforeseen circumstance, Kayn is abruptly transported back in time, accompanied by someone he once considered his most significant foe. As he delves deeper into the past, Kayn discovers the truth behind the events that led to his betrayal by both his guild and allies, as well as the agonizing reality of being abandoned by those he was sworn to protect. Fueled by a deep desire for retribution, Kayn vows to take matters into his own hands and right the wrongs of the past, proclaiming his intent to become a Kingmaker and shape the future according to his own vision.

There is nothing in the world that cannot be solved by a transaction, if there is, then make a pure (ang) clean (zang) transaction.

If you say it, you may not believe it. The people who have traded with me are all over the world.

Trading is a great cause that is beneficial to physical and mental health and that people cannot refuse!

- Description from novelbuddy

The eldest son of the assassin aristocrat Tuatha Dé.

The skill, experience, knowledge of the previous life, magic, all of which grows his power as an assassin.

Excellent assassins pass through. He was usually admired as the ideal lord, and behind it wielded a blade as an assassin aristocrat.

Seven days remained until the countdown to genetic mutation.Seven days later, all creatures on Earth would undergo mutations. Giant mutated creatures would swarm and attack humanity, putting their fate in jeopardy. The entire Earth would be ruled by these mutated beings!Yang Xiao accidentally walked into a genetic store where various gene potions were sold, capable of altering human body functions.From that moment on, he embarked on a crazy journey of genetic evolution.