Axus is a member of the Conclave.
Similar to the other three members of the Conclave, he covers his face and body with a metallic mask, a trenchcoat, and a hat. His mask has the roman numeral 'I' on it.
Axus alongside Chronus, Libraria, Baldias and Ariels was one of the Original's five Apostles who spread the arcane knowledge and influence of magic around the world. Then the Apostles (excluding Ariels) formed the group known as the Conclave with Chronus as their leader, who acts as the adviser of Sanctus Maximus Populis.
Guilty Gear Xrd -SIGN-
While Chronus try to fuse with Justice after her revival Axus went to Illyria's Castle to eliminate any threat to their plans. He then found Ky and shot him for the back, and when he was attempting to leave Ky wakes up with his new power Crimson and ends Axus' life with Rising Force.