Breyer Chorn existed as a male Mandalorian fighter during the period when the Eternal Empire executed its galaxy-wide takeover. Belonging to Clan Chorn, Breyer was recognized by his gold and grey Mandalorian armor.
Subsequently, when Mandalore the Avenger called upon the Mandalorian clans to unite against the Eternal Empire, Breyer Chorn, along with his clan, responded to the call. During the assault on the Darvannis droid manufacturing facility, he received the mission to strike at the factory's shield generator.
The initial introduction of Breyer and his clan to the Star Wars Legends continuity occurred in Star Wars: The Old Republic: Knights of the Fallen Empire. In Chapter XIV, when Breyer's unit found themselves surrounded by Skytroopers, players were presented with a decision: to either sacrifice or rescue him and his fellow soldiers.