Lunar Veil

You conjure a tremendous area of shadow to obscure moonlight within the area, creating something akin to a lunar eclipse. The light level is lowered by two steps (though unlike deeper darkness, areas of normal light or dimmer become normal darkness rather than supernaturally dark). Lycanthropes in the area must make a Will save every round or revert to their humanoid forms. In addition, lycanthropes attempting to assume animal or hybrid form within the affected area take a –5 penalty on Constitution checks to do so.