The Deep

This article is in reference to the history of "The Deep" for information on the magic of the Deep, see "Deep Magic"
"The Deep" is an over-arching presence within the world of Wyrth. The Deep is effectively the substance and energy that comprises all of existence. From the Heavens to the Hells, the spirit and material realms, all that is came from the Deep Waters.
Before even the Age of Unity, The Deep was a tumultuous and cascading ocean of raw and unbridled energy referred to as the Great Sea of Primordia. The individual elements - fire, frost, acid to name a few - had yet to be separated into the so-called "Deep Wells". These energies pushed and pulled against each other, raging in a constant storm. At some point, for reasons not properly understood or, perhaps, lost to the waves of time, the four Primordial Gods were born from this ocean of potential. They came into being fully formed as titans made from the Deep Waters themselves. Even they failed to understand their nature and struggled to find purpose in the tumult that was their world.
After a time, the Primordials - the Warden, Watcher, Keeper, and Shade - decided to combine their powers to pull the conflicting forces apart, thus creating the Smoldering Lake of Nazir, Frigid Cape of Aludrin, Caustic Swamp of Berra, Ætherial Sea of Perdium, Crackling Lagoon of Spectros, Shrouded Pond of Kar, and Radiant Font of Grei. The Primordials bound the waters, so they could never touch again. Where the Great Sea once was, now there was a barren wasteland, devoid of anything but harsh stone. However, no matter how much of their power they poured out, they couldn't hold back all of The Deep. Small streams of energy trickled into the wastes and, where they all met, something new was formed: the Pool of Animus. All around the Pool, there were trees and beasts - grasses and birds. As these simple creatures spread, there was a great rumbling, as The Deep ebbed and flowed; even restrained, the power of The Deep would not rest. From these Deep Wells, new life sprang forth.
Dragons, born of flame and filled with a fragment of that primordial spark, crawled from the Smoldering Lake. The Strigi emerged from the Frigid Cape, shaking frost from their feathers. Slimes slowly inched from the Caustic Swamp. The Dreamers came from the Ætherial Sea. Thunder Wolves, their eyes alight with an electric spark rose from the Crackling Lagoon. Demonkind was born in the depths of the Shrouded Pond, and the Celestials were of the Radiant Font. From the Pool came flickering blue flames that simply danced on the surface of the water. The Warden saw these little lights and decided to place them into bodies of wind, stone, and clay; wood, leaf, and beast. From these, mortal life was born. Some became Chimera, Humans, and Orcs. Others were Fae or Goblins. The Warden was proud of these creations, calling their flame "Soul".
After years uncounted, the barriers that held back The Deep became weak, cracking and allowing creatures born of the Deep Wells to cross into the once-barren mortal realm. To prevent the total collapse of the walls and a return to the chaos of the Great Ocean, the Primordials sacrificed themselves, pouring out the last of their own energies to sunder The Deep in what would be known as The Great Fracture.
The Deep as it currently exists is the collection of all energy - namely magic. This magic is made possible by the energy that still seeps through the barriers and into the mortal world. Since the mortal Soul is also something born of the combination of all the Deep Wells, a small remnant of that energy exists within all mortal creatures, allowing them to connect to The Deep if they are properly trained. When using magic, a caster is drawing from the energy within the The Deep, allowing it flow through them and manifest in the material plane. Only in the mortal world is this able to be done, as it is impossible for multiple energies to coexist. Since the Heavens (for example) are made from the energy of the Radiant Font of Grei, fire magic cannot be used there because it would bring energy from the Smoldering Lake.