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？

From a strategic, objective, and self-serving standpoint, taking other tribes as one's bondmen was the best solution to the human population deficit. However, for an educated man like Baiyi, this method was repulsive.

"There's no need to be concerned with annoying details," the Archmage said reassuringly; it was as though he had read his apprentice's mind. "We can strive for an equal, humane, democratic, and slavery-supporting society..."

'What sort of civilization do you think we are... Ancient Greeks? [1] Why the hell should our progress regress? It's like you don't know the tragedy faced by every society that encouraged slavery!' Baiyi retorted inwardly.

"Oh, damn it. We can debate policies for human resource management next time, alright? Right now, our priority is to fight this war, and unite the decentralized factions and guilds so that they could help achieve our goal," the Archmage said. "Okay! Now is the time to ride out!"

The Beginning