Rebirth: Building the Strongest Party with my Overpowered Harem. - Chapter 2: Rank upgrade.

Merged into the body of External Disciple Chen Yu was the heart of a demonic god.The heart is the core of life, the most fragile vital organ. To Chen Yu, however, the heart was his greatest strength, granting him power and potential beyond demonic and divine beasts. Here on out, we follow him as he embarks on a mysterious and wonderful journey.

I lived for you in the last lifetime, everything I did was for you, yet you wanted me to die; so, this time, life is mine to live! This world lied to me, betrayed me, and humiliated me, and I am back to change everything!

- Description from Novelupdates

Roan crossed over and became an FBI agent.

Several years later, when interviewing the world-renowned detective Roan Greenwood, the reporter asked:

“Excuse me, what made you persevere on the road of solving the case?”

Roan tilted his head and glanced at the sports car beside him, the villa behind him, and the beauties in the villa, and smiled slightly:

“Of course it’s the bonus after solving the case.”

“???”

- Description from novelbuddy

“Martial Arts World...” Death murmured, shocked by the turn of the events. How could he, primordial being of the afterlife, get tricked by a mere human? Not just a mere human, but also earthling, race that was weakest of the twenty realms. Death realized the extent of his mistake. An earthling had just jumped into the river of the reincarnation, where he definitely didn’t belong. It was too late. The damage has been done. The matter was now out of his hands. “Kiernan Hunter...” ... Remake of the Martial Arts System, and while the concept stays the same, the story is completely different. A few names, etc, stays the same, but mostly whole new story.