Shadow Evocation (Volcanic Storm)

You tap energy from the Plane of Shadow to cast a quasi-real, illusory version of a volcanic storm spell. Volcanic Storm: Chunks of hot volcanic rock and clumps of ash pound down when this spell is cast, dealing 3d6 points of bludgeoning damage and 2d6 points of fire damage to every creature in the area. This damage only occurs once, when the spell is cast. If an affected creature succeeds at a Will save to disbelieve, it takes only 20% damage from the attack. For the remaining duration of the spell, heavy ash rains down in the area. Creatures inside this area that failed their Will save upon entering the area take a –4 penalty on Perception skill checks and the entire area is treated as difficult terrain. At the end of the duration, the rock and ash disappear, leaving no aftereffects (other than the damage dealt).