The cursed sword wielded by Caius, the blade is home to Bahamut's evil eye.
Chaos's Revenge (リベンジオブカオス, Ribenji Obu Kaosu?, lit. Revenge of Chaos), also known as Caius's Sword and Soul Devourer (ソウルデバウア, Sōru Debaua?), is a recurring weapon in Final Fantasy series associated with Caius Ballad. Bahamut's eye is placed in the sword's rain-guard.
Caius uses the Chaos's Revenge as his weapon, able to use it with one hand despite its size. The sword can also be used as a shield to protect Caius while he is in his defensive stance.
A replica of a well-worn greatsword.
Caius wields the Chaos's Revenge with unchanged battle performance.
Lightning can acquire it under the name Chaos's Revenge by defeating Caius in the Temple of the Goddess. It is classified as a greatsword, raises both Strength and Magic by 600 points and Quick Stagger 75%.
Chaos's Revenge appears as a knight sword.
Caius's Sword appears as a greatsword within upper rank rarities.
The Soul Devourer is a Warrior-type weapon.