Sebastian Yarrick is an Imperial Guard Commissar, famous for his involvement in the First, Second and Third Multiverse wars. There he fought against the forces of the Forsaken leader Sylvanas Windrunner and Helghast commander Mael Radec. Yarrick was already old when the war began and was scheduled to retire on the day the Coalition and Axis landed. He possessed an excellent history serving with Alliance Joint Military and a reputation for unswerving loyalty, even when his native homeland joined the Imperialist Alliance. In his youth he had learned the galatic language from a human captured by the xeno raiders and was one of the few recognised experts in the Alliance on Xeno psychology and culture.