David Cain is a supervillain in the . He first appeared in Batman #567 (July 1999), and was created by Kelley Puckett and Damion Scott. Fictional character biography The assassin David Cain is one of the world's premier assassins, whose victims have included some of the most famous and powerful people on the planet. He trained the young Bruce Wayne with some of the skills that he would use as Batman, although Bruce has never used some of the more lethal techniques Cain taught him and has since surpassed his teacher in ability. Regarding his decision to train with an assassin, Batman explained, "Knowing how to kill doesn't mean you must kill". Cain desired a perfect partner with whom to carry out his assassination plans. Attempts to train young children resulted in failure, so he decided to conceive one himself. He found the perfect mother in a martial artist named Sandra Wu-San. He watched her duel her sister at a tournament and concluded that it was her sister Carolyn that was holding Sandra back from her full potential. He murdered Carolyn and ambushed Sandra with the help of Ra's al Ghul and his League of Assassins. In exchange for sparing her life, Sandra agreed to bear David's child and leave the child in his care for him to train. The child, Cassandra, would be Cain's "One Who Is All", whose native tongue was one-on-one combat. This gave her the ability to read people's intentions simply by their body language. The latter was a special gift that only the Wu-San sisters and Cassandra knew. After bearing his child, Sandra set out to become Lady Shiva. The father Cain trained Cassandra in every imaginable form of violence, from hand-to-hand combat to weapons and explosives. Cain never taught her to read or write, and even avoided speaking in her presence; her only language was her ability to read people and predict what her opponents were going to do. His training methods were tantamount to child abuse. When she was 8 years old, Cain took her to kill a businessman. After she did, she "read" him as he died, she saw death as the man saw it, commenting: "Terror and then... nothing". It was this reading that made her decide that murder was wrong and she ran away from Cain, Cain musing in hindsight that he simply pushed her too far too young. Cain