The Shaping Imbalance of the Great Collision

The fates and cycles of both worlds changed when Theus, the tempestuous realm of several primordial titans, ancient linnorms, dragons and giants, was sent colliding into the world of Aeth.
It was believed that the cause of this catastrophe was due to a travelling force of Eldritch Interlopers, that saw the worlds between and believed that conquering this place for their own more easily, would set the planets crashing into one another through the connected and powerful psionic power they possessed. They crashed into and buried themselves deep within the core of each world and awaited the destruction of the world - slumbering for eternity. The worlds were pulled to one another - the Ethereal and the Elemental Chaos together, and resulted in a strange occurrence. As the worlds collided, the Essence of Life enraptured an outburst of power that shrouded the world in an ethereal veil - all life between the worlds were caught in the veil, sustaining their lives within the Border Ethereal ... but the worlds themselves were utterly destroyed, and the Essence of Life pulled the worlds as one, uniting the spirits of the world, throwing away the balance beheld within Aeth, and interrupting the eternal war between the denizens of Theus. They call this event, the Great Collision.
After the fallout of thousands of years, the two planets merged to create the foundations of the modern world - Aetheus.
The newly merged world of Aetheus was left with the greater powers that ruled from them once before - the Primal Ones of Aeth, and the Primordial Titans of Theus & the ancient Linnorms. Each of these factions sought to reclaim the return of their dominance or harmonious balance of nature within their world, as the territorial and hardy primordial titans sought the destruction of the Essence of Life to return to the cycles of destructive elemental energy in place of the natural nature magic.
The Primordial Titans were so repulsed by the new world, caught between darkness, the Ethereal Veil and the beauty of its light, they divided the borders of the world to create the separate Planes of the Ethereal, Shadow and Fey: thus came the Ethereal Realm, the Shadowfell and the Feywild. The dead, dying and tormented spirits were consumed and trapped within the Shadowfell - no longer was there the immortal standing of the Titans, as they began to learn that they can bleed. The place in which was considered too 'bright' by the Primordials, it was fashioned into the Realm of the Faerie, granted an intermingling spirit of the Elemental Chaos, its chaotic freedom, but also the vitality and brightness of life from Aeth and the Primal Ones. The last of the powerful and greater spirits of Aeth, yet unsanctified into the folds of the Primal Ones, took on its own form and gave rise to the first Fey. Simultaneously within the Feywild, the Essence of Life tried to attain balance, as a reflection or 'echo' of the world, it gave rise to new beings infused with Elemental and Primal power.
Thus came the Season Riders (god-like beings of the primeval Fey, born out of the Spirit of Life and the Elemental Chaos): first came winter, Boreas the Winter Sage - with his presence the world grew cold and icy, cooling the world after its cataclysmic collision, settling the fires that burned across its skies and lands and thawing into great oceans. This set back the Primordial for a time, but the life of the Primals stagnated in this worldwide ice age, the souls growing abundant and tormented within the Shadowfell.
In response, the Spirit of Life sent another to balance the scales. Thus came the second Season Rider, Eostara, which allowed the reinvigoration of new life, the birth of many new things and beings, even amongst the primordial beings of Theus. But the world constantly swayed back and forth into periods of mass death and mass birth, with not much time for life to last. The balance was still out of place.
Thus came the third and fourth, the twin Riders, Freya the Summer Maiden & Vernoron the Harvest Lord, summer and autumn, where life was allowed to boom and bloom in greatness and slowly ceded to winter. Their intrusion helped bring balance to the world and to its nature. In the midst of the ever-changing world, conflict was never-ending.
The Overgrowth, having survived the Great Collision, sought to return the world under its own sway, fighting to preserve the balance so that it can remain the most powerful being in the world. The Overgrowth spread across the world to fight off against the Primordial Titans, absorbing and consuming the elemental energies of the Titans from their flesh and bone, embodying it into the natural world to which it was rooted. But it met its great enemy, the Primal Titan Morgoron, a great volcanic mountain titan that sought to break the stability of the world, and it saw the threat of the Overgrowth as the greater challenge to the Primordials. In the meantime, the recovering Primal Furies sought refuge alongside the great deities Gwynngilliad, Bwom'sambdi and Gazenaroc - for the first time, sensing the danger of these primordial, worked together to keep them at bay whilst holding sway within the Ethereal Borders where they remained unseen and invisible. Preserving their own piece of land through their will and dominance.
As time passed, the Overgrowth and the Titan Morgoron were felled, and pieces of their remains gave new life forms - forming the two factions known as the Primals and Collossals.
Subsequently, the Great Spirits rose a following of lesser spirits, still shapeless in form, began to coalesce into the visages of their Great Spirits avatar - formulating the progenitor's shapes of the Gnolls, Minotaur, Sahuagin, Tortle, Grung, Bullywugs, Grippli. Led by the most ancient, Gwynngilliad, and his second, Bwom'Sambdi - maintained the Spirit of Life, granting life of longevity with the Eternal Tree and decaying the life essence of the spirits and the Primordials themselves to create balance. Many died and many spirits reigned, even Great Spirits rose and fell to the Primordials, Linnorms, Overgrowth and the Collosals during this time.
Through the bonding of both worlds, the primeval world of Aetheus adapted the cyclical nature of time from Aeth - reanimating through the power of the Spirit of Life. Thus, gave rise to the new Primal Cycles.