Belladonna B.D

Orphaned since 5 years old, she was adopted by an organization that trains orphans to become top class assassins.
And indeed she became one. On her 10th birthday, she killed a corrupt politician. On her 11th birthday, she already had an estimated 70 kills. And when she turned 16, her kills rose up to 600 in a year making her the youngest and most efficient assassin in the world.

She had only 2 rules whenever she's on a mission. First, Kill. 2nd, Enjoy. But when the organization was infiltrated by the World Police, she was on her own. She accepted private jobs from left and right, making her the youngest billionaire in the world.

But when she turned 18, the World Police caught up to her. Imprisoning her in the World High-Security Prison. Thus, keeping her right under the world government's nose.