Spiral of degeneration

Spiral of degeneration was a mind-affecting quest spell, a rare variation of divine magic, granted by the deities of the ancient Netherese pantheon: Jergal, Kozah, Moander, Shar, Tyche.

Effects
Spiral of degeneration was potent magic that affected every creature hostile to the casting cleric within radius and its effects lasted for an entire hour. The spell could only be cast with its radius, including the caster. Depending on the deity or patron who was granted powers to the caster, the spiral was activated in one of its two variations: "thought" and "chaos."

The "chaos" variation affected the fabric of reality, making magic items seize operations due to laws of magic being rewritten for the spell's duration. The "thought" variation affected the minds of individuals, changing, blocking, and distorting their thoughts. This led to them being unable to effectively use enchanted items for the spell's duration. Both variations achieved the same result but through different means.

Once the spell was cast, the effects of the spiral of degeneration had a coin-toss of a chance of being triggered or re-occur every minute. Each time degeneration occurs, all spellcasters within the area of effect forget one memorized spell per complexity level. These spells could be normally re-learned once the spellcaster was allowed to rest and study. The second effect of each swirl of degeneration spiral affected magical items in several ways. Each degradation weakened an enchantment by one. Magical items with stored charges were drained of a number of spells stored between one and ten. Enchanted items that did not enhance armor or damage had a chance of becoming mundane. All potions lost their magic, and scrolls lost a random scribed spell. Unlike other types of magic items, potions and scrolls were affected by the spell permanently.

The "chaos" various spell randomly moved its area of effect while active, and the "thought" version remained steady. Additionally, no means of magical communication was possible while in the spell's area of effect.

History
The spell dated to the days of ancient Netheril. As of the 14 and 15 century DR, it was extremely rare with only one notable magic item known that could cast the spell–an artifact of the Church of Loviatar. The Lash of Loviatar held a vast array of spells within, some were known and some yet to be discovered, with spiral of degeneration being among them.