Reeva grew up in poverty in Chicago, and rose to power with the help of her mutant ability to emit sonic waves capable of immobilizing opponents. She became a member of the Hellfire Club's Inner Circle, but considered them too conservative. With the help of the Frost triplets, Reeve eliminated the rest of the Hellfire Club leaders and now uses the organization to create a lasting peace between humans and mutants... no matter what sacrifices are required.
Reeva's power may involve more than sonic emission: it's said by several people that it makes mutants lose control of their powers. Whether this is a direct effect, or just something that happens when a victim gets sonic-blasted, isn't clear.
In the end, Reeva plans to destroy several government buildings while provoking anti-mutant sentiment, forcing humans and mutants to live apart. Reed Strucker goes to confront her, and when he loses control of his powers he explodes... taking out himself, Reeva, and the Inner Circle headquarters.
