The aftermath of the divorce hit the Smith family hard, so a visit to the Mad Max-like dimension gave both Summer and Morty the cure they needed to get away from the pain. There they engage in battle with a warrior tribe with guns ablazed. Summer successfully kills their weakest member, earning her the right to join the tribe in order to strengthen their number. She readily accepts and quickly befriends one of its associates: Hemorrhage.
Hemorrhage only has a passing memory of his childhood, one supposedly happy and carefree before the big "boom-boom" occurred. Though he's forced to survive through murder and carnage, Hemorrhage is a surprisingly well-adjusted, easy going guy. He proves to be a strong leader with a clear head, if not a bit self-conscious of his physical appearance (that mustache has got to go though.) He and Summer bond instantly and their relationship quickly turns to romance.
Rick and Morty eventually tire of the Mad Max dimension and plans to head back home, but they hit a snag with Summer who refuses to follow. Rick hatches a plan and teaches the tribe to use their primary energy source (previously just a mere idol they carried around in a defient act against God) to benefit their lives, transforming their struggling scavenger lifestyle into a functioning suburban neighborhood. Hemorrhage has since married Summer, but lingers around the house as a lazy, no-good slacker of a husband. Her escapist fantasy ruined, Summer leaves with Rick and Morty, but not before Rick swipes Hemorrhage's energy source, depriving him of power.