Power Surging: Balzac was a mask Teigu previously wielded by a Lieutenant of the Imperial Army who was an acquaintance of Najenda's during her stint as General.
When worn, Balzac can tap into the wearer's body and mind and unlock its potential by 100%, giving the wearer super speed, super strength, lightning-quick agility and unparalleled intelligence. After all of the wearer's potential is unlocked, it cannot exceed that person's limits.
Its weakness is that the wearer can still be defeated by someone stronger than them, such as the Lieutenant who wore Balzac. Even with his powers fully unlocked, he was still killed by Esdeath.