Weapons have their own level and EXP gained through components. Once a weapon has gained enough experience, it can be upgraded via specific components to a second tier, and ultimately, to a third tier weapon. For each character, while different weapons upgrade to the same model at the end of the upgrade path, the "ultimate model" retains properties of the base models. E.g. Lightning may have an Omega Weapon that boosts her Magical Attack while having another Omega Weapon that refills a small amount of ATB gauge when attacking. All tier three weapons extend the ATB gauge by a segment.