The Pact Primeval

The Pact Primeval was an agreement between Asmodeus and the Gods of Good found within the Heavenly Spheres. While the both sides had fought since Asmodeus fell into the depths of the Layers of Hell, he approached them with what seemed like a truce. They would quit fighting each other, and vying for power by trying to claim each and every soul that died. Instead, good souls would go to the Heavens, and Evil souls would go to Hell for punishment. This seemed fair to the Gods, and they signed it willingly.
However, ever the treacherous one, Asmodeus had other plans. The Gods noticed that over time, fewer and fewer souls were coming to the Heavens. When they went to check on Asmodeus, they found that it was overflowing with Devils that had been transformed from the souls of mortals.
The Gods decided that Asmodeus had somehow cheated them, and was stealing their souls. To remedy this, they asked Primus to oversee the Trial of Asmodeus, as he was made to answer for his actions.