When you defeat DarkNite 5 times you get a password. The password enables the credits and you can then duel Yami Yugi. There are other passwords that enable you to duel Yami Bakura, Nitemare, Shadi and Marik. I have typed in the passwords to duel Yami Bakura, Nitemare, Shadi and Marik but I can't duel Yami Yugi anymore. When I type in his password it just displays the credits. So is there any way of dueling Yami Yugi again?