Shadowform

Feats

At 20th level, as a standard action, a shadowcaster can assume a form of pure shadow for a number of minutes equal to his caster level. While in this form, the shadowcaster is considered incorporeal and undead, gains a +2 bonus to Intelligence, an incorporeal touch attack (2d8 points of Strength damage), immunity to ground-based effects, and a +30-foot bonus to speed. The shadowcaster also gains the effects of the transformation spell while still retaining his ability to cast spells. The shadowcaster can use this ability once every 24 hours.