After Cassandra ran away, David had another child. You. Your purpose was to someday find and kill Cassandra.

When you were a child, your father sent you out to find Cassandra. You got lost in Gotham and ended up getting adopted by a villain.

You and your adoptive mother were walking down the street when you saw her. Cassandra.

One thing led to another and you two fought. That ended with you pinned to the wall. “Who are you?” Cass whispered, looking down at you.