In regards to the Kensai ability Perfect Strike (page 55 of Ultimate Combat) of the Magus Kensai Archetype, can it be used to maximize the damage of one die from a critical hit, such that say a rapier would do 6 (maximized damage die) + Str x 2 + 1d6 (un-maximized die) on a critical hit? Or, must he use the 2-point option that increases the critical multiplier meaning his damage becomes 3d6 + Str x 3? In essence, is the choice use 1 ki point and maximize damage on non-critical hits, and use 2 instead on critical hits to increase the multiplier, or can the Magus use 1 on normal hits and choose between the two options for the critical hits?