Illusion (Shadow) [Darkness, Fear, Mind-Affecting]
Level: Sorcerer/wizard 2, wu jen 2
Components: V, S, M
Casting Time: 1 standard action
Range: Medium (100 ft. + 10 ft./level)
Effect: Semiopaque sheet of darkness up to 40 ft. long, or a ring of darkness with a radius of up to 15 ft.; either form 20 ft. high
Duration: Concentration + 1 round/level
Saving Throw: Will negates; see text
Spell Resistance: Yes
You create a barrier of ominous shadow that obscures vision and deters passage. Creatures in squares adjacent to the wall have concealment against attacks from the other side, while creatures more than 1 square away have total concealment. Although the wall is not substantial, a creature with 6 or fewer Hit Dice must succeed on a Will save or be halted at its edge, ending its move action (though a creature can move away from the wall or attempt to move through again if it has a second move action available).
A creature can attempt to pass the wall any number of times, but each previous failure imposes a cumulative –1 penalty on its Will save.
Wall of gloom counters or dispels any light spell of equal or lower level.
Material Component: A bit of fleece from a black sheep.
Source: Complete Arcane