Golden Gun is a glass-cannon roaming Super, so I think it's justified for it to be able to kill other roaming supers in one-shot. It doesn't have any damage reduction (Except during the activation animation) and provides no ways to regenerate Health during it other than sitting out of the fight and letting your Recovery stat kick in. I'm not in support of Golden Gun getting a damage buff, though, I'm in support of Hammer of Sol losing 5% damage reduction (bringing it down to 50%) so it's in-line with the other tanky roaming Supers.