Agent 63: Commander Larness, formerly Lars Rail
The mysterious ISB agent who was intended to supervise Brown Fox's mission. Madar showed up instead - and so the party took the opportunity to frame Madar as the Imperial mole Brown Fox was sent to discover.
(Update: Post-Season 1 Finale - Agent 63, aka Commander Larness, was unable to meet Fox as originally planned because he was in an intense meeting with Baron Swift regarding security policies and Swift's long list of counter-proposals.)
Brown Fox and D'Gane delivered Madar to Agent 63, but were the only ones to see him. He tasked them to track down the recipients of the stolen Imperial Intel and capture them.
Later Damaria met him in his Commander Larness role at a Balmorran governmental banquet (as Swift's guest); she managed to capture some surface thoughts and images that unfortunately only helped in hindsight.
After Fox's betrayal, Agent 63 interrogated several of the team members, then was forced to hand over Damaria and Swift to the Inquisitor, who had arrived recently to investigate the disappearance of Master Xenrad. As the team escaped, they managed to injure 63 and capture him, and he is currently in their custody.
During the night Sprend found himself in the holding room, gun in hand. Lars pushed Sprend verbally over the edge, and wanting to shut him up Sprend struck the soldier in the head, ending his vicious words of hate; permanently.