Naruto System in One Piece - Chapter 531: Berserk

“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.

She roused from a pool of blood, vowing to exact retribution on those who had harmed her.

Lu Ran had long since known that his path in life differed from others when he awakened a special ability one day. Sure enough a mysterious black card appeared, giving him the chance to become a beastmaster. With his loyal husky by his side, he sets out on his path to greatness.

Yin BiYue has made the worst purchase ever. After transmigrating countless times into the bodies of canon fodder villains, he buys a ‘Fiend Halo’ from the Rebirth Company, supposedly the best aid for an up and coming final BOSS!

He’s ecstatic to finally get a villainous role where he won’t die after just a few lines, if any at all, and is raring to become the best opponent a protagonist will have… However, why was everyone looking at him with pitying eyes? Why was the protagonist rushing over to help him get out of his crimes? Most importantly, why was his ‘Fiend Halo’ just making things worse?!

Meanwhile, the intern salesperson at the Rebirth Company discovers that he might have accidentally sold a prototype White Lotus Halo to a certain villain…

- Description from Novelupdates