Ascending the Heavens as an Evil God - Chapter 24: Multiplayer Dungeon, Collaborative Mission

Skyler's story was typical. He was publicly labeled a waste with no future as a Light — awakened individuals capable of wielding elemental powers. He thought that would be the end of it. But no, apparently that was not the case.He was teleported to the 'Battle Royal' to fight, even though he had zero powers and his age and potential were 100% ineligible!To make matters worse, he was not even the protagonist or transmigrator! He was just a freaking side character destined to die young in the story! And his death served only one purpose — to bring his sister closer to the protagonist!What a pitiful ending, right?However, unbeknownst to all, he wasn't meant to die but to become the best in two other realms, and they had altered the fate of that powerful King. Yet, there was a tiny problem — he didn't remember how he became overpowered in his past.

Earth Immortals are cultivated from a blessed land.

Heaven Immortals move to and from the divine mountains.

I have a stalk of plum blossom, and I shall plunder the Will of the Heavens with it!

- Description from Novelupdates

A tree of 10,000 flowers, the world is the door.
The spells change a lot, but the hearts of the people are unchanged.

- Description from Uukanshu translation

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