Successfully complete the game once with each character, except for Pyron. Shin Akuma will appear after Pyron is defeated when using a team containing your last set of characters. Alternately, successfully complete the game in arcade mode on any difficulty setting, winning all rounds including those against Pyron. Also, have at least two Perfect finishes and at least one super combo finish in each match. Shin Akuma will appear after Pyron is defeated.