Johnny Dune was a Vietnam veteran who had returned home after being wounded during the Battle for Firebase Bravo. He had originally aspired to be a musician, but was also one of the head toughs for a local gang. While on reconnaissance in Nam, he and his team were pinned down by machine gun fire and Dune was hit several times. The pain of his wounds opened up a new channel within him and he screamed at his attackers to stop killing him. Amazingly, they did so, and Dune was able to mow them down with his own gun. He was awarded a silver medal for his actions that day, but he also had discovered that he was a mutant with a powerful voice.
Johnny Dune has limited mind control abilities. His scream is able to make people suggestible to his will.