The best deck to stop kagemaru is one that does damage to him when he use's any of the three decks.
level up!
Dark Zane.
he comes in the heros pack
there is no such a code... sucks
level 10
Complete the story, then duel Kagemaru who's about at night in the middle area, not sure what days though, and keep duelling him until he gives them to you.
no you cant
cockerspaniels that is all.
level up!
Dark Zane.
you go to menu
search yugioh wikia in google and go to the card ruling section and search for spirit caller......
Eventually you will find an old well at night, go to it and you will battle a random spirit, if you win you will get it.
its the god cards man. or exodia
he comes in the heros pack
you face him when he is a shadow rider
level 10