Luna

Luna and her little sister Celestia are two girls with powers like no other, who have been homeless and living on the streets since they were five. Now years later, their older and a stronger. One day, they helped save people from a burning building, breaking one of their rules, never of anyone see your powers. Now they've caught the attention of SHIELD, who is interested in having the sisters on the team. Knowing that it's what's best for the both of them, they agree. But the Avengers start to obsess over Luna, want her for themself. Let's see what happens next.