Hazel grew up on an Indian reservation, and she once had an encounter with a boy who did chores for her grandfather where they were at a river and he threw a rock at a beaver. Hazel later realized that this boy who angered the beaver god would turn out to be the man named Complete Carnage.
While going on a jog, Hazel was struck by a bolt of lightening. This bolt of lightening gave her the powers of the elements, and it transformed her into the being known as Radical. Hazel was under the impression that she was a superhero. At the same time, a similar bolt of lightening struck a man working in a construction site, and he would become Complete Carnage. Since Radical's powers represented nature, Complete Carnage's represented man-made structures; pitting the two of them in a constant battle.
On one of the occasions of their battle, the turtles help Radical. While Complete Carnage was choking Radical when he was inside a brick wall, Radical tore off his cement-like arm and hid it in Central Park. He follows her there and they battle. In a bid to win the battle, Radical uses her "particle beam" power which transfers the two of them to the dream world. Radical would continue to fight Complete Carnage in the dreamscape in order to keep the damage done to the real world to a minimum.
The turtles soon learn of the battles in the dreamscape with the guiding intervention of Radical's dead grandfather who enters all of their dreams. He specifically chooses Donatello as the main vehicle to help Radical because of his knowledge of Native American lore. The turtles soon travel to the area of a neon buffalo and meet the struggling Radical. They help her regain her energy and she performs a ceremony where a thunderbird appears to help guide her in the quest to stop Complete Carnage.
Eventually, Radical and the four turtles trick Complete Carnage to come to the dream world and they attack him near the neon buffalo. As Radical distracts Complete Carnage, she cries out for Donatello to remember the incantation. As Complete Carnage drags Radical into the pavement, Donatello recites the incantation and the Sly Fox works his magic to turn the pavement into water. The sudden change scatters Complete Carnage's molecules thus defeating him.
Radical is later seen at Splinter's funeral consoling the turtles.
It is later shown, in the future, that Radical and Leonardo develop a relationship that extends
to even the spiritual. They travel the world together and revisit the site of the neon buffalo. Back in New York, Complete Carnage suddenly appears and snaps Radical's neck. Distraught, Leonardo travels the world until he finds Complete Carnage to forgive him for Radical's death. Unfortunately, Leonardo bursts with anger and kills Complete Carnage making it his final kill.