One Piece: New Order - Chapter 4: Marineford

Zhu Kang, a trafficked soul, was captured by an evil organization and was stripped of his real memories. Unaware of the dangers he worked for this evil corporation as a system.One day, all of a sudden, fifteen men dressed in black started a shoot-out killing all the other systems.In desperation, Kang threw himself into a transmigration device that tossed his soul into a random world.“System 202 has escaped.... a-again.....” one of the black-clothed men said. Trembling, he glanced at their team leader.Kai Alden gritted his teeth. “You let him slip away so easily! Send me into that world. I will capture my dear System and bring him back here,”

The young lord of a small and weak country saves a dragon beside the sea one day.

Waking up again in his seventh reincarnation, prince Jing Beiyuan found himself back in time, when everything had yet to be set in motion. Having been given a second chance, Beiyuan had to survive court and decide whether it was finally time for him to let go of his feelings; all while trying to handle the youthful, innocent force of nature who had suddenly barged into his already complicated life.

- Description from Novelupdates

Many people wish to become a character in a novel they like. Side characters are the best ones to reincarnate as. And Ceaser was the same. However, the problem is, the person he reborn as, was supposed to die at that time when Ceaser appears in the fantasy world. The childhood friend of the main heroine, who was supposed to be a stepping stone for the main lead so she can grow stronger. However, now that Ceaser was in that person’s body, naturally, he couldn’t let himself get killed just after rebirth. But what consequences will he bring by staying alive? And what awaits near the end of this story, about which even Ceaser is unaware?