A practical man in his thirties, Miller is the commanding officer of the "Taboo Breaker" squad. He holds the military rank of a Major, and is also the husband of Ryner's master, Germer Kleisrole. He is extremely sharp and intelligent and often called a genius, and the brains in Sion's revolution. He was originally asked by Sion to become the Field Marshal due to his abilities veteran experience and seniority in Roland's military affairs, but rejected the position, preferring to work behind the scenes, gathering and developing talent, gathering intelligence, and managing covert operations.