Maoyuu Maou Yuusha - Volume 4 Chapter 4, “Having Come to Such a Time, Hesitation is Forbidden.”

【Children, remember this. Among the fortunes of heaven and earth, three parts are the essence of literature, seven parts are martial, and one part determines the fate of the realm!】【...10...3+7+1... Hey? Ancestor, something seems off?】

Riku Barusak is a hard-working child. Despite possessing an innate superior physical strength and having withstood harsh training she fails to unlock her talent as a spiritualist. The failure results in her being thrown away by her family.

Abandoned, the only ones that extended a hand to her were the demons, the greatest enemies of the human race. Serving under them as a soldier she becomes a weapon of human slaughter, a fiend that should never have existed.

Six months ago, tens of thousands of black phantom towers appeared all over the world, floating above the cities. Chemists, physicists, religious people… all of them could do nothing.

Six months later, people became used to the towers and no longer paid them attention.

One day, Tang Mo saw a flying insect crash into it instead of going through it. The next day, a sharp and clear child-like voice issued an announcement to all humans.

“Ding dong! November 15th, 2017. The earth is online.”

The black tower’s three iron-clad rules:

1. Everything is explained by the black tower.

2. 6 o’clock to 18 o’clock is the game time.

3. All players, please strive to attack the tower.

- Description from Novelupdates

I, a mere con artist, was unjustly imprisoned in Tantalus, the Abyssal Prison meant for the most nefarious of criminals, where I met a regressor.

But when I used my ability to read her mind, I found out that I was fated to die in a year…

and that the world would end 10 years later.