Cassandra Cain

Cassandra Cain is a character in the DC comics who donned the mantle Batgirl. She was born to two assasins David Cain and Lady Shiva.

She was trained from childhood to be a great assasin and martial artist. As a result of her training, she was mute and illiterate. She can only communicate with others using sign language. Batman meets Cassandra in the No Man's Land storyline and learns of her past. Regardless, he took Cain under his wing and gave her the Batgirl costume.

Cassandra eventually turns to the dark side in One Year Later and becomes the leader of the League of Assasins. She also became a member of Deathstroke's supervillain group. It was revealed that Cassandra was drugged by Deathstroke at somepoint. Robin injects a counter serum to snap her out of the trance. Cassandra regains her conscience and tries to kill Deathstroke but Nightwing interfered.