Wrath of the Mad God

A large cloud of purple, red and black mist appears in an area with a 100-foot-radius sphere. Each creature inside must make a constitution saving throw. The fog ignores masks and other attempts to block entry into the body. The fog does 20d8 damage, that is randomly chosen from the table below for each individual creature inside the fog, on a failed save and half as much on a successful one. The damage type is picked from any of the rolled dice.

Additionally creatures that fail are drowned in madness and attack the closest creature to them. The creature can resist this effect by rolling a wisdom saving throw at the end of each turn.

At Higher Levels. When you cast this spell using a spell slot of 10th level the range and area of effect is doubled, and 10d8 damage is added. Additionally creatures inside can only make the madness save once and if they fail they are stuck in madness until magically dispelled by an equal or greater magical force. Due to the overwhelming power of the spell, if it is cast using the 10th level, the player cannot cast it again for a day.