Psychic Storms can come about from the psychic deaths of many people in the same area. The psychic energy released from these deaths sometimes lingers, trapped, where it coalesces into a nimbus of psionic potential. The githzerai, slaves of Penumbra, studied this phenomenon in secret at special events, watching as dozens, sometimes hundreds of mind flayers busied themselves with the cranial cavity of fellow slaves. Over hundreds of years, many died unraveling this mystery, one that the mind flayers were well aware of. They considered it a forbidden lore best left alone. Others picked it up in secret, studying a nimbus with a lot of psychic energy. Eventually, they figured out how to trap it.
The first time a psychic storm came about was in the Incarsabec Rebellion (1531 HE - 1544 HE). In this civil war, the slaves spread psychic viruses with some success. Githzerai rebels created the first psychic storm by collecting the psychic energy of an elder brain named Igtat. When he became no more, the storm Igtats Thoughts began.
A psychic storm is to be used in the last resort, when you are willing to die for the cause, wrack the lands with nightmares, and wipe out all sentient life. The effects are rapid, with confusion, loss of psychic energy, and then the draining of your memories until you are a simpleton that has forgotten everything that you have ever learned, and over the next few hours your intelligence slips away until your nothing more than a vegetable.
- Invalak, Head Metapsionic Instructor of the Thought Trust - "Psychic Storms of Ghífthauk"
Creating a psychic storm is beyond the skill of any lone mentalist. It requires dozens or even hundreds acting in concert. It is an unwholesome act, requiring the death of many under unsavory conditions, torture, or as the mind flayers of Penumbra, grand banquets where dozens of brains are consumed simultaneously. The process now requires a containment measure to collect the psychic nimbus. Once collected, it is enhanced and amplified with psionic powers. Once released, it becomes a psychic storm with only one desire, feeding on sentient minds. It has no thoughts, only a natural instinct the survive.