Marcy and Mari (Maribelle) are two sisters who lost their parents in a house fire and ended up in an orphanage that belongs to a secret organization in Gotham that trains children to be assassins. Mar -who trained her ass off for years- does everything to keep her younger sister -Mari- safe by doing all the headmaster's dirty missions. One mission, she was tasked to kill the billionaire playboy Bruce Wayne as a last act and then he will let the sisters free, Mar -determined to be free from the headmaster's control- puts her life at risk to kill Bruce at the Gala and fails miserably (facing off against the Robins), Bruce sees the fire in her and decides to hear her out instead of handing her over. Somehow with Bruce's influence, Mar and Mari managed to escape and Mar managed to get Mari adopted to the family, herself included, from there, the sisters' real adventures begin.
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