Indigo
Indigo has no "true" identity. "He" is known only as Indigo, and using the pronoun "he" is arbitrary, as Indigo's gender is far from certain. A master of concealment, Indigo can blend into any scene, whether it be a dark hallway or a crowded room. "His" presence is simply not registered if Indigo doesn't allow it, despite "his" blue skin. Indigo is able to infiltrate any secure area, as well as perform feats the equal of master escape artists, allowing "him" to get in and out of dangerous situations with ease. Indigo is also the tactician of Sovereign Seven, expertly organizing the team and constantly finding ways to execute Cascade's often demanding strategies.