Sage Monarch - Chapter 28: Open Clan Fighting

Hiding in the Cold Palace and eventually becoming a Boss of Sorts. Li Mu was transported to a fantastical world and became a measly eunuch of the State of Xia. Despite having initially thought that his life would be a miserable one, he had unexpectedly acquired a check-in system.

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.

There was a time where I was summoned to a different world. I spent more than a year as a Priestess from a different world. I fulfilled my role and decided to return to my original world. Before leaving, I confessed my feelings to my escort knight. And from there I was heartbroken. After returning to the original world for a year and half, I was summoned again. What? Apparently this time, nobody summoned me. I was sent out to a great extent and have a lost love. I cannot face anyone now! No one knows that I was a former Priestess and I can only quickly return to my original world. Even so, it does not seem to work out very well…

That lonesome night as he lays dying in the hospital, fearing of death and desiring the taste of life, his mind became unprecedentedly complex with mixed emotions.