The Betrayer Gods are an informal collection of beings who, while once all under the banner of Worship of any of the Betrayer Gods is strictly forbidden in the vast majority of places, though their worship does secretly happen within cults., now often follow their own goals. Many were risen to the level of 'God' by dark means or The Betrayer himself and are entities that originated on different planes. They were major players in every Sundering that occurred, and are now locked away in separate dimensions, though still able to reach out with their power to communicate with people on the material plane and influence them.
The First Sundering occurred when The Betrayer betrayed the rest of the gods by empowering other primordial beings and bringing them under his rule in order to gain more power and dominion over the mortals that so annoyed him. He also twisted and enslaved the second race of chromatic dragons to his will and they were forever corrupted. This led to the first war between the good and bad 'gods', lasting for years and decimating the mortal population before many of them were locked away and banished. Since then they schemed to escape. The Second Sundering occurred when some of them managed to break free of their prisons. This time, they were able to start rescuing their fellows and wreak havoc amongst the mortal population. In order to ensure that they would never be able to free The Betrayer and to limit their influence on the material plane, the first generation of gods cast a powerful magic that would keep them all banished to the Abyss, unable to reach mortals apart from through emissaries and whispers and dreams. They continue to try to empower and free themselves using the cults that spring up around them, to little success as their cults and servants are endlessly hunted.