Pact Prime Evil

The Pact Primeval is a powerful document signed by Asmodeus and the gods of law that assigned Asmodeus the position of cosmic jail warden. The gods were tired of having to deal with wicked souls personally, so Asmodeus (a former angel who, with his minions were designed to defeat the primordial chaos of the universe---read: demons---and in the course of fighting with them, began to take on their evil characteristics) volunteered to be the one to deal with evil souls.
This deal involved Asmodeus being given domain over the Nine Hells, since the gods didn't want him splattering the blood of wicked souls all over their polished marble floors in the Heavens. Asmodeus began his duties and as outlined in the Pact Baator and the nine layers were created; but the gods soon realized that Asmodeus and his Devils began to not only deal with the evil souls but actively began corrupting and entrapping souls to ensure their damnation. Amadeus himself was siphoning power off the souls of the wicked mortals he was capturing.
The gods were aghast, but apparently, they didn't read the fine print. Bound by their own Law’s they have been unable to find a loop hole and fighting the power of Baator a double edged sword. For while Pact Prime Evil is effective Baator and the Devils must fight the Blood war and not the heavens or angels.
The Pact itself is written on three copies, one in the Heavens, one in Mechanus, and one in the Nine Hells. Each copy is an artifact of overwhelming good, overwhelming law and overwhelming evil