The Proof of the Pillar is an item carried by the Pillar of Cephiro. Its form can range from jewelry to weapons.

When a new Pillar is to be chosen, the item of proof will transform according to that person's nature. For Princess Emeraude, the proof became a tiara embedded with green jewels, made to be worn around her forehead rather than on top of her head. For Hikaru, it became a sword made entirely of fire, save for the hilt.

Due to Hikaru's abolishment of the Pillar System, the Proof of the Pillar has disappeared.