From Halopedia, the Halo wiki
Brothers of Unending Ire
For the better part of a decade prior to 2560, Arthoc wreaked havoc on UNSC operations. While serving under Korth the Wrender within the Brothers of Unending Ire, he would participate in various raids on human colonies. Arthoc himself would lead almost four dozen individually documented attacks on colonial sites, with the most notable being a vicious ambush on the UEG colony of Terceria that claimed the lives of three entire squads of Orbital Drop Shock Troopers. Eventually, Arthoc and the rest of the Brothers of Unending Ire would pledge allegiance to Atriox and join the Banished.
Arthoc participated in the Installation 07 conflict, serving as part of Dratix Pack in the Second Combat Element of the Brothers of Unending Ire. On January 31, 2560, Arthoc joined Chieftain Tremonius as he led a massive Banished force in an attack against the UNSC personnel entrenched at the crash site of the UNSC Mortal Reverie. The overwhelming assault forced the surviving UNSC to retreat from the crash site on February 2. Later on during the conflict, Arthoc was located and identified as a high-value target by the Weapon. The AI passed this information on to Spartan-II John-117, who hunted down and killed Arthoc and the forces accompanying him.
List of appearances