Cassandra was raised by David to become a formidable assassin, and she ultimately became a skilled martial artist able to effectively read body language the cost was Cassandra learning to read, write or speak.
Introduced in 1999’s Batman #567, which was in the middle of the No Man’s Land crossover storyline, Cassandra Cain is the daughter of assassins David Cain and Lady Shiva.
Found by Barbara Gordon, who has long been Oracle by this point, Cassandra became one of her field agents.
After killing her first target, Cassandra felt immense guilt and ran away from her father.