A dormant metaphysical reservoir of unbridled, unaspected elemental energy that lies beyond the physical bounds of the plane of Rhyst.
Compared to its Planar Sisters, Rhyst is in more manageable discord and harmony between the elements that comprise its existence. But should its essence teeter dangerously towards Extraplanar extremes, between Faewild and Void influences, it is the Planar Convergence that would allow it the opportunity to engage in a total 'reset', liberating itself from 'Corruption'. Life swallows itself whole in extreme weather conditions; land shattering earthquakes, swelling oceanic storms, deafening hurricanes, and raging wildfires. From this return to square zero, this near-extinction event, once more would life begin to flourish, and what little is left would take to the remnants of toppled civilizations and devastated monuments, growing over the pieces and redefining the natural and man-made history of the plane. It has been this way for countless millennia.
But Life, and its unyielding spirit in the face of the endless, astral cycle of destruction and rebirth, must draw upon something with each new cycle. As Flora and Fauna meet their end, the following release of what mana had been passively accrued through their existence is released into the Plane. What is not repurposed through the natural cycle, or processed through its harvesting and consumption, is left to linger in what is known as The Wellspring. It is not a place souls go, nor any mortal could enter. But, when a life is lost, well-lived or otherwise, the mana they held within them at their time of death contributes like a small tithe for this Reservoir as the Soul returns to the Cycle. As eons pass, the infinitely massive Wellspring fills and diminishes. Its contents deplete and replenish. It is not a 'force', and has no particular alignment to even the plane it gets its namesake from- It is simply an abundance of mana that Rhyst has been passively accruing over time that is drawn upon as life ebbs and flows throughout the plane. It is not hostile, it is not beneficial- It just exists.
It is abnormal for any being to actively tap into the Wellspring: It is not something achieved through any amount of practice, nor through any amount of research. In fact, it almost seems accidental when that connection manifests in a being. What can be done through this connection is the subject of thorough investigation with very little tangible result. Little is known on how the Wellspring is tapped into, though those who access it tend to have extensive history with extraplanar experience, or are regularly subjected to the horrors of the Void and Faewild.
It is a trait rooted firmly in the art of spiritual healing; It is the only known 'link' between people who have been able to access the Wellspring.
It also tends to crop up in people who have strange encounters with Planarbound beings (Spirits, Faewild and Void Beings).
More Wellspring users appear when a Convergence is about to begin- A phenomenon that spirits may recognize more often than mortals might.
People have a saying of a Soul weighing 21 grams, that leaves a body when it dies? There's an extra tenth of a gram that goes to the Wellspring. Debatably.