In 1945, Lucifer himself took note of the increase of souls arriving in the Hells. Even those pure of heart and firm of faith saw themselves stuck in the infernal bureaucracy. So Satan ventured to confront his father, only to find Heaven gone. The pearly gates were shut, and there was nothing beyond.
The sovereign supreme returned to the Hells shaken by this new reality. Suddenly finding himself the sole ruler of the afterlife, he kept the disappearance of Heaven a secret, and sought to change his realm for the betterment of all souls. The Hells would remain a place of torment for the damned, yes, but also a paradise for the worthy.