Heal my broken heart - Cherryberry
Blue helped people. People who were the subject of abuse, mentally, physically and sexually. Red was a victim of domestic abuse - left out on the streets because he was weak, with life-threatening injuries. When Blue found him, Red was dying. He had given up on the world, thinking that he was weak. But Blue showed him he wasn't.
(Has a lot of angst, sadness, depression, triggering material, swearing, sad flashbacks, etc.)