Press [F10] to enter the options menu, then enter the configuration menu. Type spam to enable cheat mode.
Start a new game with two players, with one of the players using Juggernaut. Allow the player controlling Juggernaut to defeat the other player. Have the losing player press [Start]. Press [Start] on Juggernaut's face when it appears, then have the losing player quickly press [Start] when the "Space Port" stage appears.
Enable cheat mode. Enable the "Free Play" option at the system menu.
Highlight Spiral, wait three seconds, press [Left], wait one second, press [Left], wait one second, press [Left], wait one second, then highlight Iceman. Then, press [Right], wait one second, press [Up], wait one second, press [Left], wait one second, press [Left], wait one second. Omega Red should be highlighted. Press [Down], wait three seconds, then press [LK] + [HP] + [HK]. Akuma fall onto the screen to confirm correct code entry.
Enable cheat mode. Enter the system menu and enable the "Boss Select" option. Save the modified settings. Start normal game and select a fighter and block mode. Hold all three punch buttons down (to fight as Juggernaut) or all three kick buttons (to fight as Magneto) just before the match begins to load. Release the buttons after the match finishes loaded.
Type god at the message screen. The phrase "God mode enabled" will appear. Exit the message screen. The phrase "Sinister has changed the cheat code" will appear at the top left portion of the screen. In this mode, fighters will receive greater damage.