An alien character from the Halo franchise, introduced in Halo 2. Originally a highly-capable Covenant fleet commander, 'Vadam was disgraced and condemned to death following the events of the first Halo game and his failure to prevent the destruction of the titular ringworld. Forced to take the mantle of Arbiter, he would survive and ironically ally with the man responsible, and the two would work together to bring an end to the Human-Covenant War.
