Seven Unfortunate Lifetimes, All Thanks to a Single Moment of Impulse - Chapter 14

Kaelen Dragonyx, a boy who lost both his parents and his mentor in the most ruthless way possible, decided in his heart to become the strongest swordsman in the world to protect the last remaining family he had, which is the only child of his mentor and his childhood friend.But along the line, he discovered that he is the most talentless boy of the generation which made his road towards being the strongest swordsman to be much further away and daunting than he could imagine. Be he didn't give up until he stumbled upon a sword that drastically changed his fate.

Being given a chance and reincarnated is nice and all, yet why do I have to become that male friend who just watches the protagonist flirting with his harem?---World: Kaguya-sama: Love Is War - Hyouka ----

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.