Magistorm

Magistorm, sometimes referred to as Arcanestorm, Rain of Magic or the Cries of the Wise One are an unnatural and unpredictable phenomena on Tethys. Nobody knows why it happens, many speculate that the solar system was once a great battleground and a lot of magic was dispelled here, thus some of it returns to the planet in the form of rain. The coming of a Magistorm can be predicted to the last hour as the clouds will gain a strange colour tint that would change every couple of minutes, many believe it is the magic energies that gather in the clouds. Instead of turning dark or grey, the clouds gain multiple colors, while the rain itself is colorless like normal water, its effects are dangerous. Most living things are safe if they can find some shelter. Prolonged rainfall can change the landscape, either by bringing a new harvest or killing the plants. Some dangerous forms of Magistorm could bring Aberrations or change animals to such creatures. Magical items that need recovery could be left outside to recharge. Some wizards pay handsomely for bottles filled with magical water as it is as good as Etherite. The Magistorm might be the inspiring point for the creation of Arcanite.
After The Second Divergence a new type of event happens during a Magistorm, called a Magihail, when some of the rain has very white hail that can destroy objects and harm creatures just like normal hail. However, there are two things about this magihail. One is that it is very dangerous as a creature who is hit with it might contract Grey Chaos, where the impact will turn the skin gray and they would be transformed in some way. Like, an arm hit with the magihail will change "race", so they might gain a wing, have it slender like an elf when they were an orc and such. Others that might turn into Aberrations. The second is that if enough magihail falls, it will disappear over time, as it is magically turned invisible and flies away to a safe location where it combines itself. This creation forms a new Aetherborn. Nobody ever saw and recorded such an event, thus it is mostly speculated that they are created at the same time as they appear after magihail.