Entity Intervention
"Some gods die; others but slumber, and in their dreaming wait for a dawning hour and movers prime, and the opening of a gate." - The Thanatosian Tomes. From a 1623 translation by the Marquis De Rais
Make no mistake of it, all powerful mystical entities are interested in the balance of the cosmos. This is how they are assured of the maintenance of their spells.
Entities that are considered good, "white", or striving for Order are interested in maintaining the balance. The other entities, dedicated to evil, "black", or Chaotic philosophies and given to dreams of conquest and increased power are constantly trying to usurp new domains and unbalance the universes.
Because Earth seems to be a nexus for so many dimensional apertures, and because so much magic interacts there, the status of this location is of great interest to most entities. Many is the time a daemon has attempted to conquer the Earth dimension, and many are the entities that are successfully entreated to provide energy for spells to fight these would-be conquerers. A few entities are completely neutral, such as the In-Betweener, but those are rare.
Because mankind can sometimes be as greedy, petty, or megalomaniacal as these daemons, it is often easy for a daemon to recruit new Earthly followers and believers to his cause.
Cults spring up constantly, dedicated to this entity or that, and sworn to the takeover of the Earth dimension by that being. It is up to the mages and sorcerers of Earth to help keep the balance of the cosmos by opposing these chaotic cults, magicians, and entities in whatever way they can, whenever they can.
Equally dedicated are the entities who are benevolent and wish to assist these Terran wizards in their fight against Chaos by answering their entreaties.