Who is Muriz from Children of Dune and what is their importance?

Muriz is a Fremen. He first appears when he is putting his teenaged son, Assan Tariq, through the test of manhood required by the "Cast Out." Muriz next appears as the leader of a band of paid renegades operating at Shuloch. He finds Leto II Atreides in the desert, foolishly draws a pistol on him, is disarmed, and forced to become Leto's wadqiuya (blood brother), something that guarentees Leto's safety among the smugglers. Muriz later fails to prevent Leto's fleeing into the deep desert.