They say when you make a pact with the devil your soul will be forever taken and you will send to depths of hell.
Well not for some special people.
Their a certain people who had a powerful spiritual power which makes it hard for the demons to take hold of their souls.
The deals are still up but theirs a catch to this deal.
The demon/dealer and the human become partners till the very end.
Now it doesn't end there, the two had to fight other people like them so they can keep living and to grant the wish they want.