Page 7 of my comic Lethally Evil Issue 1, this is when Natas is offered a job into collecting souls for the "master" but he already knows what the demons are up to, and its his job to keep demons in hell, not let them out.
"When a demon gathers up enough souls from other dead demons depending on their power, they create a portal that reaches as far as the human world, and in order to escape hell once and for all, they must be reborn again through a human sinners blood and bone, of course they must be fully dead in order for a demon to burst out of them. But they wont last very long in the human world, with Natas's brother guarding heaven's gate and the human world, his job is to keep demons off earth if they do escape hell."