The stakes are even higher for Sam and Dean Winchester (Jared Padalecki, Jensen Ackles) in the second season of Supernatural. Though they continue to fight vampires, witches, and other famous baddies, their top priority is finding a mysterious yellow-eyed demon named Azazel. The powerful creature was responsible for their mother's murder, as well as countless other deaths. More powerful than anything the brothers had conquered in the past, Azazel is able to abduct Sam. To his dismay, Dean is forced to make a decision that may haunt him for the rest of his life.