Serenade

Born with both sonic powers and psychological problems, the girl called Serenade was kicked out of one prep school after another. She finally ran away from her wealthy family, and at the age of seventeen killed her first man--a thief who tried to rob her--with her vocal abilities, and realized killing wasn't as hard as she'd always thought. When a drug kingpin discovered her abilities, he put her to work for him as an enforcer, and gave her a new life. It was a good life for a while, but when he tried to become abusive, she killed him, took a load of his cash, and headed out on her own again. Finding that she'd liked using her powers the way he'd had her doing, she developed a costumed persona and began hiring herself out to others. Her final job had her working for a man named Mr. Dusk, who told her an invasion from a race called the Karrigon was coming, and she would be on the right side when it all came down, and have a place in their new world, if he helped her. This made sense to her, and she took the job. She ended up battling a new team of Seattle heroes that were trying to stop it. During the fight, the heroine Tinker used one of her imaginative non-lethal weapons on her, one that fired fire ants. And ants filled her mouth and nose and swarmed all over her, and something about that moment of horror and terror snapped the last of her sanity. In the following fight, she attempted to kill Tinker, went into a rage, and, cutting loose with her sonic powers, brought the roof of a department store down on herself, ending her own troubled life.