Void Elemental School
The void is a complex idea considered by some to be a fifth element—one that comprises thought, space, spiritualism, and insight. Arcane knights who tap into its mysterious powers gain control over energies that bind the earth to the heavens and the planes to their mysterious and eternal alignments, as well as the powers that stitch living beings to their spirits. An arcane knight who specializes in the void element must select a single element (air, earth, fire, or water) as his opposition school. An arcane knight must expend two spell slots to prepare a spell from his opposed elemental school as normal. An arcane knight of the void elemental school gains the following powers.
Reveal Weakness (Su)
When you activate this school power as a standard action, you select a foe within 30 feet. That creature takes a penalty to its AC and on saving throws equal to 1/2 your caster level (minimum –1) for 1 round. You can use this ability a number of times per day equal to 3 + your Intelligence bonus.
Aura of Prescience (Su)