Spellstorm

“It was our fault, we should have paid more attention to where we were. We knew being in The Bleed would cause issues for us, but Genki, our mage, told us the walls of reality are weaker here and the closer we get to the Great Barrier the better. It started so peacefully. Then the air went still. It was scary. We could all begin to feel the hair on our body stand up. Then we saw it moving over the horizon in our direction. We should have left then, but when it got close enough to see it was not a normal storm it was too late. It was homing in on not only Genki, but Marigold as well. It was fast, drawn towards our sources of magic. It was accelerating, we had to move, but then the first bolt erupted from the cloud…”

The Spellstorm, also called a Mana Storm, is a phenomenon found on worlds of high magic. Thankfully it can only form in areas where the walls between realities have weakened, reducing the places it can form. They look like regular storms at a distance, but as you get closer to them, you start to notice odd things about the cloud and bolts. The colours are off, the sounds appear to be muted or sharper. To the lazy or uneducated persons eye, they just appear to be a regular old storm. To those that wield magic, they are deadly clouds of energy and destruction.
In essence, a Spellstorm is formed when a normal regular storm is infused with high amounts of magical, non-divine energy. They start off as regular storms and can grow and shrink as the regular versions do. As the storm grows and absorbs more magical energy from the environment, this energy is stored in the cloud. At a critical point, it starts to ignore the winds and currents that push it around and starts to seek out other sources of magic. First, it draws from the local environment, temporarily reducing the arcane power found there. Then once it’s exhausted that it starts to move further and further. Sources of magic act like magnets, drawing the storm towards it.
However, that stored magic energy has to go somewhere. Some of it goes towards weird and wonderful clouds of various shapes, colours etc. The rest gets channelled into what gives the Spellstorm its name. As the storm cloud moves closer to a strong source of magic, bolts that resemble lightning can be see erupting from the cloud. Any mage, spellcaster or person with a magic item unlucky enough to be hit or be close to a bolt from a Spellstorm has all their spells fire off at once. Those spells that require a target use the poor victim as the target, in effect they target themselves. The energy of the spell temporarily overrides constraints such as required materials, but if a spell has a side effect, such as making you older, or reducing your health permanently, these effects are activated as well. The most powerful storms are to be feared, as they can trigger every spell the mage knows to go off at once, not only the ones they have prepared or stored.
Most mages who live near places where Spellstorms occur have lessons drummed into them by their teachers and companions. A few locations have built mage-shelters that seem to help prevent the storm from activating their spells. There is also a persistent rumour that somewhere there is a small town that is trying to draw power from these storms on purpose.