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The art of Omnomancy, or its practical application of Omnotheurgy is a misunderstood art, and one where the true power behind its spells are limited mainly by the imagination and intelligence of the caster. Omnomancy is the arcane manipulation of magic to achieve effects based around reality, time and magic itself.
Omnomancy requires understanding of advanced concepts, so it usually is not found in lesser civilized areas. Being able to control the very essence of reality, time and magic grants Omnomancers a lot of power, which has lead to a lot of fear by those not fully aware of an Omnomancer's capabilities.
With the Omnomancer's capabilities of manipulating time, there have been multiple instances throughout the ages of Omnomancers interacting with periods of time other than their own. Omnomancers frequently discuss the possibilities and repercussions of paradoxes, but there is no concrete evidence as to their existence or effects.
During the Second Age, the Planar Council's wizard schools and colleges started getting together to discuss what would eventually become Omnomancy. Several years after they had enough material to develop and start teaching, a Omnomancer from far beyond time arrived and started to share his knowledge before disappearing as quickly as he appeared. Being able to also control and manipulate magic at its basic form grants them almost a level control over all other forms of magic, and even other wizards view Omnomancers differently.