Origins
The elves were not a species born from pure aether, nor were they shaped by the wills and wants of the gods beyond. Rather, they were a species born from a series of accidents and coincidences—all perfectly lining up to make them the species which they are now.
This long-winded process would begin when a species of tiny multicellular organisms would wander into a cave with an abnormally high level of aetherflow. Due to their small size, the constant high exposure to aether would greatly affect the organisms, triggering rapid and uncontrollable cell growth amongst most of them. Many of the organisms would die off in a matter of days, but those that were able to survive would evolve to be able to handle the high aetherflow environment they were exposed to. This evolutionary process would happen over the course of just over a century, as the process was exasperated by the high death and reproduction rates of the organisms, as well as the high aetherflow which heavily assisted with their evolution.
A few more centuries would come to pass as the multicellular micro-organisms changed their evolutionary path from mere survival to thriving within their environment. They'd evolve from simple micro-organisms to complex waterborne animals, then to quadrupedal amphibians, then eventually to mammals. Each evolution would slowly lower their rate of evolution, but the aether in their environment would cause a great amount of evolutionary variations, with the one thriving the easiest in the cave being the species which had evolved to be similar to monkeys.
These proto-elves were smart and were innately aether sensitive, with both traits only growing and developing more for the good with every generation that would come. They would feast upon the fruits of plants which grew within the cave, or on meat of the other weaker creatures (particularly the fishes). This newly born species would've evolved to become cave-dwelling creatures if a meteor had not collided with the mountain atop the cave, carving out a massive opening to the outside world. Consequently, the aetherflow of the cave would lower with the creation of the new opening, causing evolution to slow and growth to dwindle within the cave. Lacking resources and fascinated by the light above, the proto-elves would make their way out into the outside world, never to return to the confines of their cave ever again.
Outside, these proto-elves would continue to thrive and slowly evolve into the form which they bore now: pointy-eared, long living, intelligent, and highly sensitive to aether. Fortunately, their legacy as a species would not end with the final steps of their evolution, as the elves would dominate the habitable lands of the Material Plane for an incredibly long time.
This dominant society would be come to known as the "Atavistians" in modern times, as any records of what they were called as a society simply either did not exist or have been lost to time. These Atavistians ruled for millennia alongside the dragons, bearing a faction which was responsible for the creation of many of the Material Plane's intelligent species.