Diabolo

Ten years ago, close friends Rai and Ren made a deal with evil: they wanted the strength to protect their friend Mio, but she disappeared and the two were blamed for her apparent ‘murder.' Their deal, like the deals of many others in the world, had a serious consequence: they became the Diabolo, and at the age of eighteen they'd lose their souls and become something inhuman. Now, Rai and Ren are seventeen and on a hunt to find Mio while they are still human. Along the way they try to help save others who broker the same deals out of jealousy and desperation, but their eighteenth birthdays steadily approach...