Three Sins Against Heaven - Chapter 12 – Merciless reaping

After being awakened by a raging headache and faint memories of his past life, Tsubakihara Yuuji found a strange smartphone he had never seen before.Opening it, he found a single question that would change his life and many others for the better, forever.[Do you wish to join the Multiverse Group Chat?][Yes] / [No]

“Primum non nocere.”

A broken man who ended his own life finds himself reincarnated into the game he used to play. However, instead of becoming the protagonist or a powerful antagonist, fate places him in the role of a minor villain—a mere stepping stone for the protagonist in the game's first arc.

The world is terrorized by the powerful Black Witch who has been sealed in the moon. Every ten years, the night of Hexennacht arrives and a chosen witch must battle the Black Witch in hopes of finally defeating her.

As the current decade’s Hexennacht approaches, a mysterious girl named Kagami Kagami arrives and meets Horinouchi Mitsuru, the daughter of the previous Hexennacht representative.

It takes place between Kyoukai Senjou no Horizon and the City Series, two other series by the author.