greater invisibility
Class: mage : 4 bard : 4 assassin : 4 inquisitor : 4 magus : 4
Syntax: cast CLASS greater invisibility

This spell, available only to masters of illusion, allows the caster to enhance the normally fragile

  distortion an invisibility spell offers. The more powerful version of this spell will not fail even if the caster 
  becomes involved in combat. However, due to the additional concentration required to maintain this stronger variant, the 
  spell has a chance to drain from the caster every time he or she moves.