Girl with the radioactive hard body
Nikki is a smart ass plain and simple. She makes sarcastic comments to stupid questions but gives honest answers to real questions. When not patrolling or fighting you'll usually find her riding around a skate park on her board. At the same time, she often gets confused around both boys and girls. While not a social outcast, her recent discovery that she finds girls attractive can make her awkward during social events. She can also be extremely clingy as a result of losing her twin sister as a young girl.
Besides her uniform and her skateboard (which has been modified with micro engines that run off her own energy) her only equipment are her powers. The result of her origin her body is filled to the brim with radioactive energy. This has caused a massive mutation as her skin and muscles act as radioactive shielding. This has increased her durability. She's recently started to learn how to increase the power of her hand to hand attacks by filling her hands and feet with small doses of her energy. She's also become extremely flexible as a result of training her body for any and all skateboard tricks.
Her history begins with a government project. Project Warrior was designed to create the perfect human. A perfect body and a perfect mind, a true super-soldier. They were supposed to be the first and last line of defense if the Meta-humans ever turned rogue. The project was a total failure. No child born of the synthesized DNA showed any signs of being anything other than an ordinary kid. The project was shut down and the families moved on with their lives. Nikki and her twin sister Nadia rode the bus to school every day until they were seven. That's when the light came. An explosion of energy over the town of Pembleton, South Carolina leveled the city. Thousands died including Nadia Thompson and her parents. Out of the wreckage four people emerged alive three children, and one adult. The four had only survived as a result of the powers that surfaced that day. They were carted off to a secure government facility for two years of extensive tests. This is a time Nikki refuses to discuss.
After the testing period was done Nikki was left in the care of her grandfather, he died when she was 13 from radiation poisoning. Thirteen people from their apartment building also showed signs. Nikki was quickly taken into custody and placed in a juvenile detention center for meta-humans. When her trial was done she was cleared of the suspicion that she'd deliberately poisoned the people in the building. Unable to control her powers she was a danger. She was tutored by a titan named Powersurge in controlling the energy in her body until she no longer leaked radiation. At the request of her tutor she was accepted into the titans alongside Powersurge, a girl who controlled the electrical fields around her, (both human and artificially generated) Shatterfist, a crystalized humanoid with immense strength (Nikki called him Crystal), and Kid Miracle, the flying fighting leader of the team. (With new and improved powers of healing)
Unfortunately with all the publicity around her trial Nikki is a very public figure with no secret identity.