Maria Waters, aka Sunstone, was one of the three founding members of the team. She's doing some kind of remote learning program for a master's in biochemistry, which she's really good at. Her power is pyrokinesis, the ability to control fire with her mind. She can only control existing fires though, so she's always got a lot of matches and lighters in her pockets. Besides those, she also has firestarter bracelets, that she can hit together to create sparks to work with. They're less effective than the lighters, but she claims they add an extra "intimidation factor." Not that she needs it; an angry Maria is already scary enough!

Maria grew up in Louisiana, and had a fairly normal childhood, at least relative to the rest of the team. She spent most of her time alone, reading and studying. When Edwin Starkweather moved in next door, the two began a brief friendship. They spent a lot of time together testing Edwin's powers, but lost contact after he moved away. After that, Maria became even more invested in her studies than she had been before. A few years later she went to a special lecture on chemistry that focused her interest on that subject. She sped through the rest of school, graduating high school at 16, and was accepted into the university of Chicago to study biochemistry. Once at university she was introduced to her lab partner, Milo. The two hit it off, and began dating.

Two years into her studies, Maria acted as assistant in a particularly complicated experiment, which ultimately went awry. Ambiguous chemiscals exploded out of beakers, lighting the lab on fire and dowsing Maria. Only, instead of dying, she gained the power to control fire. She was able to escape the fire, but didn't realize she'd gained powers until several weeks later, when she accidentally turned a candle into a fireball. Once she realized what had happened, she started working to track down Edwin. She remembered him from when they were kids, and thought that he'd be her best hope for learning to control her powers. By coincidence, Edwin and Calvin had just started putting together their team, and with Ed's reccomendation Calvin agreed to have her join the team.

She moved to Frostfield more permanently, and switched to remote classes to continue her studies. But, she was already good enough by then that she was able to become the team's chemist. When Oliver joined the team, they were forced to share the only lab. Their organization methods are different enough that they almost instantly began arguing. Eventually they were forced to work together on a mission, and gained a mutual respect for each other. Despite their constant arguing, they're now closer than any other members of the team.