One Piece: Madness of Regret - Chapter 8: The ember in the water (1)

One-eyed Wolf Lecan is a skilled adventurer who has conquered many dungeons all over the world. He had been going solo for a long time, but in the last three years, he’s had a partner. That partner jumps into the black hole together with Lecan, and both go their separate ways as they fall into another world. Dungeons and magical beasts also exist in that world. After learning the native language, Lecan goes on a journey. Meeting a good teacher, Lecan studies medicine making and magic under that teacher, and begins his dungeon explorations for real.

A data loving young man from Earth has an accident which transports him to a dark land filled with terrifying creatures and magical powers. Fortunately for him, he has a Biological Assistance Chip to ease his path. However, things in this bizarre and strange world are not always as they seem, and, though it is a tremendous asset, the chip doesn’t always work as expected. With all of the crazy creatures and magical mayhem around him, one can only wonder what the future holds for this young man…

- Description from novelupdates

In a world where magic was abundant and supernatural creatures existed, Jin Valter lived as a fallen genius. Being the son of two A-Ranked Hunters, Jin had inherited his father’s keen eye for martial arts and his mother’s innate talent for magic. Alas, before Jin could reach his full potential, an Outer Demon attack left his soul crippled and his body weakened beyond repair.

Now, Jin lives out his days bound to the hospital bed with nothing but his brains to keep him company. Gone were the days when his peers hailed him as a genius as he struggled to even conjure a spell with his body falling apart.

However, it would all change when on the Night of the Blood Moon, a unique visitor paid him a visit…

After Stargaze Family executed his family, Noel Ardagan embarked on his journey, restoring his family name with the help of a System.

"What? How the heck did she get it before me? The system told me that I'm the only one who knows about it!" Noel Ardagan cursed in anger, "That conniving murdering woman!"

"At this point in time, only I should be aware about this tomb. But how did he find out about it?" Anna Stargaze, even after her reincarnation, couldn’t comprehend Noel's actions.

The clash between of a person holding a system and a reincarnator who knows everything in the future is about to start.