You form a momentary link between yourself and the Negative Energy Plane, allowing you to release a black ray that suppresses the life force of any living creature it strikes.
You must make a ranged touch attack to hit. If the attack succeeds, the subject gains 1d4 negative levels for 1 round (see the Negative Levels sidebar on page 100). If the subject has at least as many negative levels as it has Hit Dice, it is stunned for 1 round instead.
On the following round, the subject regains lost levels. Usually, negative levels have a chance of permanently draining the victim's levels (or killing creatures with hit Dice equal to or less than the number of negative levels gained), but the negative levels from stygian ray don't last long enough to do so.
An undead creature struck by the ray gains 5 temporary hit points that last for up to 1 round.