The Double Agent of the Heavenly Demon Sect - Chapter 49

Zane Thaleward, born into a prestigious family known for their extraordinary magical abilities, struggles to meet the expectations placed upon him. Unlike his relatives, his magic is weak, limited to only the simplest of spells, making him the subject of mockery and ridicule.Despite the constant criticism, he remains determined to become stronger. One day, while searching the family’s library for a way to improve his magic, he stumbles upon a strange, ancient book. Little does he know, this discovery will change his destiny forever.

Hell Ghost Wang Wannian is born again, smiling and proud!
What?
Are you a soldier, will the tank drift?
You are a master, can you give birth to dragons and tigers?
You are a superman, can you call the wind thunder?
Excuse me, I am not targeting anyone, everyone in my eyes, it is rubbish!

- Description from Uukanshu (translated)

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

In a world where the boundaries between dimensions are thinning, a young man named Kael Ardent is thrust into the Eternal Nexus, a realm where countless worlds converge. Here, the laws of reality are dictated by Aether, a mystical energy that fuels both creation and destruction. Kael discovers he is a Nexus Warden, a rare being capable of manipulating Aether to bridge worlds and command the forces of the Nexus.But the Nexus is not a place of peace. It is a battleground for Eldari, ancient beings who seek to control the Nexus and use its power to dominate all existence. Kael must navigate this treacherous realm, forge alliances with warriors from other worlds, and unlock the secrets of his own latent powers. As he grows stronger, he uncovers a prophecy that foretells the rise of a Prime Warden, a hero who will either save the Nexus or doom it to eternal chaos.