Sphere of protection from undead

Primary and move action. Provokes. 0. 3 radius sphere. Sustain. Creates a fixed 3 radius sphere of protection from undead centred on you when you use this magic. Lesser undead within the circle are incapacitated and the outer radius prevents all undead from physically entering. This glows with a soft light of your choice and runes may be visible and even used for communication. Powerful undead caught in the sphere may make a MAG check or merely be slowed rather than incapacitated. This spell is often used to form a bulwark in order to rid an area of undead progressively, or a fall back point. The sphere is immobile, its walls of light insubstantial to the living.