When you invoke this spell, you instantly summon a horde of dozens of wrathful, screaming spirits—gray and incorporeal shades driven to slay the living. You shape these spirits into a cone, which is then directed at foes. Every creature in the area of effect must make a Fortitude save or take 1d6 points of damage per caster level (maximum 10d6). Those who fail their save must make an additional Will save or acquire 1d4 negative levels. A successful Will save completely negates this effect. Oddly enough, this spell is also effective against undead, who are vulnerable to the wrath of angry spirits.