This was because the researchers were aware of his usefulness to them, but they also feared his insubordination. As Hiroto’s usefulness increased, this fear also grew.

The explosives in his body were buried not only in the heart, but also in the brain. His torso housed a GPS to prevent his escape. His right eyeball was been replaced by an artificial eye containing a special camera and a listening device was planted in his mouth and ears to catch even the smallest whisper.

His food intake was limited so that he would never have more physical strength than necessary. His room was small and he was never allowed to leave it except for experiments.

To make him more able to use death-attribute magic, to increase the size of his Mana pool – They reconstructed his body for a variety of reasons.

In order to ensure that he wouldn’t somehow make an ally to plan an escape or rebellion, the guards who watched him and the operator that gave them direct orders were rotated often, so that he wouldn’t be in contact with any individual in particular for an extended period of time.

And finally, they carried out an inhumane procedure on his brain, cutting off his control over his body’s Mana and making him their puppet.

At this time, Hiroto wasn’t even ten years old. And from this age, he spent over ten more years in this hell where he couldn’t even move a single finger of his own accord.