Klog, from Ultima VII
Klog is the branch leader of the Fellowship in Trinsic in Ultima VII, with his wife Ellen sharing the administrative work with him. He seems at first nice enough, but it soon becomes obvious that he is a nasty person.
Christopher, the blacksmith of Trinsic, got into an argument with Klog a week before Ultima VII. When the Avatar arrived, Christopher was murdered and Klog and his wife seemed to have an alibi. Klog also wasn't very helpful in the Avatar's investigation in Trinsic. When the Avatar listened to the service Klog gave the evening after the murder, it was clear how Klog totally ignored Christopher leaving the Fellowship. The whole service was in the end really distasteful and used the memory of dead Christopher to further the Fellowship's goals.
However, later in the game, the Avatar got the truth from him: Klog had called Hook and Forskis to murder Christopher, because the blacksmith had known of the Black Gate project by then. Klog and his wife had stayed home to have an alibi. This meant that these two knew exactly of the real purpose of the Fellowship as well. Klog was even proud of the carnage and sad that because of the need for an alibi, as he had been unable to witness it personally.
It is very likely that Klog and his wife were arrested after the Fellowship was outlawed, and put to justice for conspiracy, high treason, and murder.