The Novel's Sidekick - Chapter 41 30: Fool’s Courage (1)

[The 3000th Descent of Mystery is about to begin.][This is your only chance to redeem yourself.]When the whole world was in danger, Wang Teng activated a unique talent.It was the Rank SSS talent - Inequivalent Exchange!He was not purchasing things for free, but the exchange was not equivalent.[Exchange successfully. You used half a bowl of cup noodles. With your Rank SSS talent, you may retrieve an unlimited supply of cup noodles.][Exchange successfully. You used a bottle of Sad Breeze wine to exchange for the Star Shifting Method.]…From then on, Wang Teng activated a new exchange system.

Hoarding top-tier baddies, stealing people's wives, and cucking kings and emperors. That was Dapper’s daily routine. Life was sweet… until he caught the attention of the system enforcers.Liam, a teenage thief with a twisted way of thinking, died in the middle of a high-stakes heist. But just when he thought it was all over, he met a god, a failed god, who granted him a glitched system.Reincarnated into the body of a meek teenager named Dapper, Liam finds himself in a world ruled by magic, systems, and mythical creatures. This time, he’s determined to live the life he never could in his old one. The wild fantasies he once harbored are finally within reach… but at what cost?

Shao Xuan joins a friend in his expedition to a recently discovered archaeological cave. After he picks up an ordinary looking stone he is teleported to a different world and wakes up in the body of a small orphan child. The world he is in now is still in its stone age with primitive tools made of stone and the ways of the people are savage. Savage isn’t the only thing special about the people though, because they have superhuman strength, jump higher than trees and punch stones. In short, they are able to cultivate their bodies. Despite all this, it is a real struggle to survive because of the scarcity of food. Together with Caesar, his pet wolf, he tries to survive in this cruel world.

- 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