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？

Without magic, humans were vulnerable to supernatural creatures, and this resulted in a high death toll. As the soldiers defending the city struggled to stay alive, the low-level demons seized the opening created by the demon casters to reach the city wall. The demons flung their Abyss Ivy ropes over the wall and climbed the wall, quickly reaching the parapet.

The demons were much faster than the soldiers, and soon, the soldiers found themselves overwhelmed with magic and melee attacks. Amidst the chaos, more soldiers were slain.

Only a few minutes had passed, but two hundred soldiers were already dead. The demons had suffered casualties, too, as the despairing soldiers were fighting with all they had. However, the demons had the numbers advantage, and it seemed highly likely that the soldiers would lose.

What's Going On At Mia's Side?