Fiona was born to Tricia Williams and Drew Torres. Tricia met Drew when he entered her clothing store. Instead of browsing the store for things to purchase, he went to go court Tricia. Tricia persisted on telling him to go buy something and leave her be, but Drew's charm caught her, and then they began a relationship, that ended with Fiona.
When Drew left his lover, Tricia was forced to raise a child and run a store on her own. Fiona spent most of her time in their apartment, while her mother managed the store. Every so often Drew would secretly go and visit Fiona. He had told her not to say anything to her mother, and she kept his promise. As Fiona grew older, her father's visits slowly ceased to a stop.
When Fiona was twelve, she was taking a shower, and her body began to radiate heat. Her body became so hot that the water that was hitting her was evaporating into steam. The amount of the steam in the room increased to the point where it made it very difficult to breath. She ran to the door, coughing. But when she touched the knob, she put her other hand on the door and lay her head down to try and get more air. Her body's temperature had increased to the point where Fiona's body was engulfed in flames. Therefore, the door was now fire. The ring of the smoke alarm echoed, and the door was kicked open by her mother. Then she, along with the fire, were sprayed by a fire extinguisher. Her mother then gasped at the realization of the flickering flames around Fiona's body. Her mother knelt besides her and explained to her, in the nicest way possible, to leave the house before you do anymore damage. Fiona packed a few things, and left to find a new home.
When Fiona was fourteen, she caught fire, and the police began hosing her down. She sunk to her knees and let out a girlish yelp. She was then rescued by another mutant by the name, Issac Denton.
Fiona was taken to Issac's apartment, where she rested and regained her strength. They exchanged their stories and became good friends. After, Fiona accepted Issac's offer to live with him as long as she needs.
Fiona and Isaac lived like this for a while, until they heard a distant explosion. The duo sprinted outside, and they were hit by a colossal wave of energy. Their own flesh burned, and Fiona tried to scream, but nothing escaped her lips.
She woke up to a world of complete chaos. People were behaving like animals. Thieves and rioters filled the streets. The next year, the two had scraped off a living with their mutant powers, which were enhanced by the energy around them. They then found out that their was a "police force" who called themselves the Panacea, who said mutants were a plight on the world, and it was their job to expunge their sickness.
They took out the first group of Panacea with no regret. Fiona scorched them alive with her powers, and Issac crushed the Panacea's mind with his powers and crushed their skulls with throwing knives.
One day, as they were taking temporary residence in an abandoned hotel, Panacea filled the building. They were pushed into a corner, but the crowd split into two, when a hispanic man walked through the crown of Panacea.
The man simply looked him in the eye and grinned. "Prepare their medicine. They need to be cleansed." The man contacted Fiona through her mind, telling her to focus all her power and create a small volcano. With all her might, she succeeded. The volcano erupted, killing all the Panacea members, but the man still stood unharmed by the lava that was touching his skin.
"Have fun while you can, children. We all have to take our medicine at some point." The two escaped and soon ran into a group of mutants who took them in, who they still remain with, as they wanted to help them in their efforts of mutant liberation.