Galo Escárcega was a member of the UNSC Marine Corps’ special forces and ORION supersoldier. Already a proficient and deadly operator, Galo’s recruitment into the first phase of Project ORION forged him into one of the deadliest soldiers in human history, only being surpassed later on by the advent of the SPARTAN-II Program. Following the collapse of Project ORION, Galo spent most of his time on his homeworld of Madrigal as a trainer for Army and Marine Special Forces. After the fall of Madrigal during the Human-Covenant War, he began taking an active role in combat operations against the aliens. Following the conclusion of the war, many surviving ORIONs, including Galo, left the military for the private sector where there skills would be more highly valued. Galo himself would go on to become a highly rated mercenary and hitman, occasionally encountering former comrades.