Sixteenth Basket of Mantaos

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!

EndlessFantasy Translation 

Why Did You Summon Me？

Since evening until night, Baiyi had been giving lessons to Tisdale and Mia in his very own Magus Lab.

The subject was Elementary Magic Formation, a subject Mia had dabbled in before. It was also the basic prerequisite for any Rohserlian sorcerer.

It didn’t go too well for the two girls. They were as confused as a deer caught in headlights. They did try hard to learn despite their confusion, and it was clear that while both were slow, Tisdale made more progress purely because of her natural aptitude.

"Alright, that’s all for today." Seeing their lackluster progress, Baiyi could only stop his class. He gave the girls the reading materials he had prepared beforehand. "Study this."

Peaceful Times