Cloak of Dark Power (Evocation, Alteration)
Components: V, S
Duration: 1 round/level
Casting Time: 4
Area of Effect: The caster
Saving Throw: None
This spell creates a dark aura of coursing, swirling, power around the caster. The priest's body and anything worn or carried (by the caster only) are protected by this aura from the effects of full sunlight, even under the open, daytime sky of the surface world (arms and armor imbued with the radiations of the Underdark don't begin to lose their power, and the drow caster suffers no "bright light" combat penalties). This magic specifically fashioned to prevail against a light spell.
A priest shrouded in a cloak of dark power functions as if one experience level higher, in all dealings with undead. Arachnids (and others using arachnid forms) attack a cloak - wearer at -3.
Source: Source: Greenwood, E. (1992). Forgotten Realms Menzoberranzan. UK: TSR