Wolf of the Blood Moon: A Blood Magic - Chapter 26Book 6:

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]

Wang Yi was reborn into a world that swallowed the starry sky. After eighteen years of ordinary and extraordinary, he finally met the conditions on the eve of graduation from high school, activated his own golden finger, and signed in for the first time.

[Ding, congratulations to the host for successfully signing in, signing in for the first time, and signing in to the earth, special rewards will be given to reward the first karma of the Nine Tribulations Secret Code! 】

[Your genetic level has increased three times! 】

“…”

Imagine being forced to live, after death, as incorporeal bodies trapped in a vast space of nothingness for thousands of years, with nothing to do but exchanging past memories with other cohabitants (read: weirdos). Everybody wanted out, but there was no way to leave the Void…

Until one day, a young man was finally summoned, as a powerful but reluctant mentor, by a bubbly and motivated but completely naive young girl. Baiyi, finally out of the Void, was the only one who could save all of the other 32 souls from their prison and his summoner might just be The Key to their freedom.

However, Baiyi had to use the techniques and abilities the other souls had taught him throughout the years, and together with his own extensive knowledge of anime and game tropes from his shady and dangerous past as an otaku, to face the biggest challenge of them all: training the clumsy young girl he was forced to partner up with… into a competent sorcerer!

This is a story of heroic adventures, cunning strategies and romantic tales. How will our MC thrive in a world completely strange to him? Where will his ambitions and abilities take him in the palace?

- Description from Novelupdates

Instead of causing chaos with my knowledge of the original work, I assisted the protagonist.

I successfully completed the story and now planned to retire and live peacefully.

However, it seems the protagonist still needs my help.

An academy professor? That’s nothing much.

But why is the state of the academy so strange?”