SCION (Secure Command Intelligence Operations Network) is the Union's 'high security' internal AI. SCION deals with the high level requests and as such is usually not in contact with elites on a constant basis. As with ARTHUR, SCION is fully sentient, and can exist outside of the mainframe with "personal" memories, though it is ill-advised for him to do so. He is similarly programmed to have high loyalty to the Union.
(credit for the name goes to Shannon)