Legion No.X, also known as Phantom Thief B, was a notorious thief from Semuria who wore a mask and cape while committing his crimes. He had an obsession with beauty and saw Kroze as particularly charming. Estelle referred to him as "The Pervert Mask." Despite this, he worked with Weissman's plan to steal "Hope" because he believed that the faces of those who resisted and clung onto hope were beautiful. In Zero no Kiseki, Legion No.X traveled to Crossbell and participated in a subquest where he stole a statue and hid it in the mayor's bedroom.