Shadow Evocation (Ice Storm)

You tap energy from the Plane of Shadow to cast a quasi-real, illusory version of an ice storm spell. Ice Storm: Great magical hailstones pound down upon casting this spell, dealing 3d6 points of bludgeoning damage and 2d6 points of cold 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 snow and sleet 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 snow and hail disappear, leaving no aftereffects (other than the damage dealt).