One Piece: Don't Worry, I'm a Doctor - Chapter 159: Now Standing Before You Is: Combatant Merry!

He, since childhood, had followed the Foreigner to practice the Defying Heaven Art, entering the most secretive special forces and becoming a fearsome assassin that made others tremble at the mere mention of his name. After a single failure, he took early retirement, but he ended up as the personal bodyguard for a rich heiress, a school beauty. Accidentally provoking some mysterious Cultivators, he gradually unveiled a hidden world of Cultivation beyond the mortal realm...

A series of short stories in the world of Toaru Majutsu no Index organized into chapters featuring Kanzaki Kaori as the protagonist, going around the world and space doing missions for the Church of Necessary Evil, however, there is more than meets the eye as each incident is connected.

One chapter was bundled with each limited edition release of the Toaru Kagaku no Railgun anime DVD and BDs, with all of them together being equivalent to a single normal Toaru Majutsu no Index volume

The main character Lei Yu does not have the ability to practice his family’s martial arts. He gets stepped on and tossed around. Due to certain reasons, he leaves the family, coincidentally gains an ability, and makes his own path to becoming an immortal.

- Description from Novelupdates

On the Yuan Continent, fantastic beasts and powerful cultivators exist. Their immense power is capable of shattering mountains and emptying oceans.

On this continent lives John Fenix, an unfortunate youth who is unable to cultivate and wield such immense power. He could only powerlessly look up to others and watch as they soared to heights unseen.

After a fortuitous encounter with a mysterious object, John finds himself able to cultivate. Determined to never feel powerless again, he sets out on a cultivation path filled with danger and excitement. Utilizing powerful cultivation arts found within the mysterious object, John sets out to write his own legend and ascend above all as the Immortal Asura.