Welcome to the gang. You are now officially part of Monoculus!
Monoculus (モノキュラス, Monokyurasu?) is a group of bandits situated in the desert of the Dead Dunes in Lightning Returns: Final Fantasy XIII that searches for the treasures and relics buried within the sand. It is lead by Oerba Yun Fang.
Many gangs of bandits used to operate in the Dead Dunes, plundering the treasures that once filled the ruins here. But now, only the gang known as Monoculus survives. Based in the outlaw settlement of Ruffian, they are the de facto government of the desert.
The members of Monoculus are fiercely loyal to their leader and proud of the bonds that hold their group together. They see all of the ruins in the desert as part of their territory, and they watch diligently to make sure that the holy clavis is not stolen in the rush that follows the unsealing of the ruins.
Thirteen years ago, Fang left the care of the Order of Salvation in Luxerion and ventured to the Dead Dunes in search of a long-lost relic called the holy clavis, becoming the leader of Monoculus. When Lightning awakes from crystal stasis and is made the savior, she comes to the Dead Dunes following the rumors of the clavis, and ever since she leaves the Dead Dunes station she is being monitored by Monoculus under Fang's orders. When Lightning finds the Monoculus's settlement, Ruffian, she meets Adonis and asks him about the clavis, but he won't divulge what he knows unless Lightning joins the gang. As a trial, he tasks Lightning with stopping God's Wrath, a bothersome sandstorm. After performing the deed, Adonis welcomes Lightning into Monoculus and brings her to Fang.
Fang accompanies Lightning into the temple ruins and they find the holy clavis, which Fang tries to destroy. She reveals its purpose and her reason for seeking it to Lightning: Fang wanted to find the clavis to keep it away from Vanille since the Order plans to use her as a sacrifice to destroy the souls of the dead through a ritual called the Soulsong, which only Vanille can perform since she is now a "saint" who can hear them. Having been led to the Clavis Chamber by Lumina, the Order's Secutors gain possession of the clavis and take it to Luxerion. Fang decides to disband Monoculus and meet Lightning in Luxerion on the world's final day to stop Vanille from sacrificing herself.
- Oerba Yun Fang (leader)
Monoculus is a Latin word meaning "one-eyed". A single eye is the symbol of the Illuminati and is also a symbol of spying.