He was born into the wasteland and lost his family due to radiation poisoning and Infected waters. He was taken in by executioner after fighting his way there while he was 8 years old and also lost a bit of his ears due to some fights on the way there. He has a talent for crafting weapons out of basically nothing and is really good at handling guns (that's where the name comes from). He was also tasked with assassinating Miles once, which failed and left him wounded. Gunner later dies in a explosion, which buried him in the metro underground. Although hes a survival expert, he couldn't get out and died due to dehydration and starvation