Why must the devil be Defeated? - Chapter 25 - 024 Duty and Reserve

In a world where fate is scripted and power determines survival, Arthur Nightingale was never meant to shine.When he awakens in the world of Saga of the Divine Swordsman, he isn’t the destined hero, the villain, or even a major side character—he’s an extra. A nobody. A mere background figure in the shadow of Lucifer Windward, the overpowered protagonist who will one day ascend beyond gods.But Arthur knows the truth.The world he now inhabits is doomed. The plot is destined for a catastrophic downfall, and the so-called “geniuses” will not be enough to stop the tide of destruction. Armed with knowledge of future events and his own will to defy fate, Arthur refuses to be just an extra.

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