Chaos

Chaos was the first cosmic being in the universe, from which all other creations originate. It is an perpetual churning undefinable power, constantly shifting its essence and being. It is the personifcation of disorder, creation and creativity and shares the cosmic balance along with Good, Evil and Law.
Chaos created everything before destroying it utterly, a never ending cycle of creation and destruction, until it created Law. Together with Law it created the foundations of the known multiverse, most notably the Weave of magic as well as the abberations, forces of cosmic Good and Evil and the Great Elder beings.
After the settling of the cosmos, Chaos has been become more bound by the cosmic balance of power. It now only wields direct influence in its associated cosmic planes as well as more limited influence in the prime material planes (and its Feywild and Shadowfell echos) through conduits from the Astral Sea. Of all the four major cosmic powers, Chaos has by far the most influence over the Far Realms.