Quote Originally Posted by Skyblade
Wait. If Barrett's weapon is based on AP in the Materia, you get no bonus if you put Master Materia (Master Command, Master Summon, Master Magic) in his weapon? What about Enemy Skill?

Of couse, for the space of a single Materia Slot, you can get an infinite boost, by equipping Underwater, since it has no max AP, and it can't be mastered. I've gotta try that...
As Master Magic/Summon/Command materia and Enemy Skill materia neither have nor can accrue AP, they cannot contribute to powering up the Missing Score.

Unfortunately, the Underwater materia (which actually does cap at the three-byte integer 16,777,215, and then resets) cannot be applied to the Missing Score. All that extraneous AP doesn't help; the Missing Score will treat it as zero.