MTL - Rebirth: Rising Hong Kong - Chapter 1558 Yan Xiong's majesty!

The NPC sets out on a journey to defeat the Demon Lord, joined by beautiful girls he meets along the way.---This is an NSFW story, so if you're under 18, turn back now, son. No NTR, and no full-on Yuri. There might be slight Yuri—like girls kissing and stuff during threesomes—but it's not that kind of Yuri where the girls fall in love with each other while in a relationship with the MC.---

Master said, the woman I held in my hands, I must protect for the rest of my life.

Master said, it’s hard to cultivate as a Demon, and once you enter the Demon Dao, you should never look back.

Master said, Heaven is a Circle and the Earth is a Square; that Circle represents (is) consummate perfection, and that Square represents (is) the edges and corners of one’s Heart, it’s a rebellion against Fate, a Disobedience to Heaven.

My master is named Ning Fan, he’s not a person, he’s merely a Butterfly who has entered Demonhood. He was searching for someone. No one knew who he was searching for. No one knew how long he would search for…

- 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