Five Remaining Heavens
From Threesong
Shortly before the rise of Homer, the Sixth and Seventh layers of Mount Celestia ascended to a state of eternal bliss, never to be heard from again. The remnants had little to offer in the way of explanation, to outsiders or to themselves, and their loss of leadership led to a loss in interplanar relevance. The survivors are tenacious though, and have made great strides in their relations with the yugoloths (see The Way of the True Apocalypse.