Discipline Strike (Ex): A 3rd-level Master of One has perfectly internalized the principles of his favored discipline. He takes techniques and footwork from various maneuvers and combines them to produce a strike that only an adept familiar with his favored discipline has a chance to counter. To use this ability, a Master of One makes a single melee attack with a bonus equal to the number of strikes of his favored discipline he has readied, with the bonus divided between an attack bonus and a damage bonus, as desired. For example, if a Master of Diamond Mind has readied 9 Diamond Mind strikes, the bonus would be +9; the Master could then make an attack with a +9 attack bonus, an attack that deals an extra 9 damage, or any combination of attack and damage totaling 9.
How often can you use this? Is it a once-per-encounter, once-per-day, once-per-hour, at-will, or etc. ability?