The Demons Rising

A heart blackened by time, now reserved for hatred and despair. Vengeance-achievable through reaching the afterlife and gaining ultimate power-is the only way to satisfy an unquenchable thirst for justice. But, when a resurgence of hope blurs the line between retribution and madness, the blackened heart seeks to preserve what beauty is left within its grasp.
Neeksus had hopes of life, until death seemed the only path. A voice beckons him to commit a final atrocious act: he must take the lives of as many individuals as possible, as well as his own. Once in the underworld, all will be made clear.
A boy named Gabriel suits the requirements for Neeksus to attain his goal, residing in an earlier time and among space separate from the Milky Way. This boy holds a single hope: a girl dear to him, belonging to a fate worse than death.
Neeksus can save her, but only if the boy kills and collects countless souls. Many will die, who will be sacrificed in Neeksus's quest for revenge...