Rare Boxes

Rare Boxes are like Attack Boxes, however with a twist. They contain powerful moves like Seed Flare, Sacred Sword, and Dark Void, but can only be used once as opposed to once per battle. All of them require Tesseract or some variation of the HM in order to be obtained. The player also cannot pick up a Rare Box without first learning more about them from the Box Shop in Constance City.

Special Litwick
In Canis Town, there is a girl who wants the Rare Box for Seed Flare. If you give her this Rare Box, you get a Litwick with the moves Shadow Ball, Fire Blast, Moonblast, and Shadow Sneak. Litwick cannot learn Moonblast or Shadow Sneak by any other means than by getting this Pokémon.