Cult of the Quasar
The Cult of the Quasar is a dark cult devoted to their master Azathoth, and his sergeant, Eos. While the dark cult occupies parts of Eon and are considered extremely treasonous, they're also recognized in multiple dimensions as well.
Not all of Delta's evil forms are involved with the cult, but Delta does have speculation that they may be influenced by a form of hers that's especially active and even orchestrating the entire movement. Because of this, it makes it all the more prudent for Delta to hunt them down and take care of them.
There's also speculation that the cult took Walter , Catastrophe and Carter's father, and that he's being used as a weapon by them due to being connected to Athaza.