You place yourself in a state of unresolved probability. You are trailed by several faint reflections of yourself, slightly out of phase with your own movements—these are echoes of possible probabilities.
While the duration lasts, the images create a blurring effect that grants you partial concealment (20 percent miss chance)—since these images are all potentially equally 'real,' true seeing and similar effects cannot pierce the concealment. More importantly, while the duration lasts you may reroll one dice roll you have just made each round (be it an attack, a saving throw, or some other in-game roll—for instance, you cannot reroll a poor Hit Dice roll when you gain a new level). You must take the result of the reroll, even if it's worse than the original roll. You do not have to make any rerolls if satisfied with your normal rolls, but you cannot store up unused rerolls.
For each 2 additional power points you pay past the end of the stated duration, the power lasts one additional round.