I'll Teach You, Marianne. - Chapter 731 - The Loss

Shao Ci was bound to the ‘Befriending the Most Powerful Person’ system. After crossing through, only then did he discovered that as long as a more powerful person emerge, this unscrupulous system will immediately change the ‘capture’ target….

- Description from Novelupdates

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

Struck down amid the battle, the Hero and Demon King meet their demise. As their souls linger on the edge of the afterlife, a mysterious force intervenes, merging their fragmented souls together with a new being. Rusty, the living armor, now affected by their memories and presence, embarks on his own quest. Will he seek revenge on those who betrayed the hero, or will he fulfill the desires of the fallen demon king? or instead, forge his own path?

There is always such a person in the world, his family background is better than yours, his status is higher than yours, while you work hard and think all the way up, but with just a wave of his hand, you are wiped out. What is even more sad is that he doesn’t even know who you are.

Zheng Jue met Han Jin like this but he didn’t realize this truth until he died. In the end, he had found the wrong opponent and ultimately lost his life.

- Description from Novelupdates