brother-in-arms

brother-in-arms (plural brothers-in-arms or (rare) brethren-in-arms)

1. comrade in arms (fellow combatant or soldier)

   Coordinate term: sister-in-arms

   • 2010 February 18, Evan Narcisse, “Wrex in Effect, or, Deep Space and the Negro/Injun/Krogan Problem”, in The Atlantic‎, archived from the original on 02 September 2013, Culture‎:

     But the vengeance I told myself I was getting for Wrex felt like a lie. I could win the game but he wasn't coming back. Being forced to lose my in-game comrade-who I thought of as a virtual person of color and as a brother-in-arms-affected me in a forceful way that I never expected. Mass Effect made me look at myself and think about the way races, classes and individuals bring their histories to bear.

• battle buddy