Project Bolt is a failed experiment that was the cause of death to many people in a facility. It Bolt was the power 'given' to the boy. Previous lives don't matter anymore. Bolt was his codename. When he escaped, he left that name alone. It didn't matter anymore. "My sister is what matters, idiot."
(Based on our own story.) A boy that was hurt and scarred by everyone. Another that everything good he had was taken away. A girl that lost everything in the blink of an eye. Another that had it all. When they cross paths. What would happen? Only time will tell.