Simple here pick your top three battleborn you think would sacrifice themselves for everybody else and explain if you would like
Why: montana is pretty much the most caring person who puts all others safety above his own, I can easily see giving some battleborn a chance to escape varelsi hordes while montana holds then back, with oscar mike getting depressed at what happens yet know montana died happy knowing he protected the people he loved
Why: benedict has lost most of everything, including his family. In his final hours I can see him find redemption and atone for how he treats the other battleborn, going out like montana similarly, and finally seeing his kids and circinae.
Why:now let me explain, the reason I see this happening is it seems the battleborn are people he may actually have a soft spot for. I can see him and the battleborn stuck in a big facility that the varelsi have overrun, and in a twist tells everyone he will sacrifice himself by activating a self destruct sequence and tell the battleborn to run as he does, yet acting like he is only doing it because he is old, yet in the end looking at a picture of him with the battleborn, having a tear in his eye, not of cowardice, but a sad happiness knowing he is saving people he cares for, and as the varelsi almost reach him as he listens to classical music with a tear in his eye, the facility explodes,leaving the battleborn sad for the person they once thought they hated