Erin Garnet is a character appearing in the anime Brigadoon: Marin to Melan. She is a Gun-Swordsman, identifiable by her pink color scheme, and her primary weapon is a rapier. Her background is tied to the forces of Brigadoon, where she originally fought alongside her comrades Pyon Silver and Melan Blue. Her perspective on this bond changes when Melan defects from their group to protect a human girl named Marin Asagi, whom Melan believes to be the true Creis Marine.

Erin's personality is notably callous and pragmatic. Unlike Melan, who shows some restraint, Erin is uncaring if humans get hurt or become collateral damage during combat, and she is willing to kill them if she deems it necessary. Her driving motivation for much of the series is her belief that Melan is a traitor to their former alliance. She is determined to destroy him for this perceived betrayal and serves as a direct opponent to both Melan and Marin.

Despite her antagonistic role, Erin's function in the story evolves thanks to the persistent kindness shown by Marin. It is through Marin's influence that Erin eventually changes her allegiance, leaving her original faction to join Melan and Marin's side. This shift in loyalty demonstrates a key development in her character, moving from a rigid enforcer to a more flexible ally. Her redemption is highlighted through her actions, as she later uses her abilities to help provide an antidote when a Proliferation Promotion Monomakia causes a human character, Moe Kisaragi, to grow exponentially.

In terms of notable abilities, Erin's combat style is defined by her use of a pink rapier, which distinguishes her from sword-wielders like Melan and Pyon. She also possesses special disks that she can deploy at will; these are capable of deflecting incoming energy blasts, adding a defensive layer to her offensive capabilities. Her eye color is noted as being blue or green, though her physical appearance is otherwise primarily defined by her armored form.