The Villains Need to Save the World? - Volume 1 Chapter 5: Chance Encounter with the Forces of Light

He died on the wedding of the girl he had a crush on, after a long and successful career. After convincing Yama to send him back to the world, he decides to fix the areas in which his life went wrong. Realizing the lack of love and romance in his past life, he sets out to conquer the hearts of various women.

- Description from Novelupdates

He became a teacher at the best magic academy in the empire.
….For being mistaken for someone else.

Xiao Qingrong had no mother and no father. With his own ability, he climbed to the peak of life, then encountered a system who could shuttle him across time and space. “Do you want to become a male god?”

He turned into a 17-year old, weak chicken with two years left in prison, Xiao Qingrong coldly interrogated the system. The system, playing dead, threw a powerful pill.

#In short, this Male God always threatens his Super Male God System#

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