He is a bald man who wears a monocle over his left eye.
A calm and serious individual. He is also amoral and willing to euthanize members of his group if they failed him.
He was the supervisor for the Group of Terror, but unlike Gozuki, he would treat the five inhumanely, locking them up when they didn't succeed easily. After their first mission turned out to be disastrous, Gozuki euthanized Remus due to her being the weak link of the group.
Much later, Akame would assassinate him and his assistant, though Uncle Bill would attempt to attack by buffing up to a stronger form, only to be killed instantly.