Power Stones

 are items that can be used to unlock new Accessory Powers.

Mechanics
Power Stones are used to unlock Accessory Powers that are not obtainable by default. of the same Power Stone can be given to Maxwell to combine them, unlocking a new Power that can be applied to the player's Accessory Bag. Each Power also gives a unique stat boost while that power is in use, although this bonus is not increased as magical power is increased.

Trivia

 * Many Powers inherit their names from old Accessory Reforges, and some even have the names of which the stones used to provide (Shaded, Sweet, Silky, Bloody).