Select versus mode, then hold L + R while selecting a character at the selection screen. Your character portrait will remain the same, but you will appear as a monster during the game.
Successfully complete the mission from Mikan in the Clinic at the end of Chapter 4. After then, talk to Mikan to view any movie.
Note: This trick only works on Xbox Live. You need at least three people in the same lobby. The type of game should be an ante battle royal game. The host should make an arsenal composed of skills he does not care about losing, since he will be the only one losing. When the game begins, have the host press Start and then go to "Return To Lobby". Next, when the host is in the lobby he or she must kick everyone in the game. When the person is kicked, a "You Win" screen should appear, and you will attain the other people's skill that you won. Because this happens for everybody, everyone wins. No one actually loses skills, they are just copied. Everyone will get skills and nobody loses them except the host. You can have players take turns being the host.
At the beginning of a duel either in multi-player or scenario mode, as the timer is counting down if the skills you have in your arsenal are bad or you do not have any Aura Particles to start with, press Back before the timer reaches zero. You will reshuffle your starting skills. This can only be done once per duel, but it is a good way to avoid a bad situation. Additionally, for every thirty Xbox Live wins, you will be given one of forty Xbox Live skills.
Always have at least eight to nine Auras in your arsenal, or else you will be lacking in Aura at the beginning of the mission and waste skills. Also, have a balance between long, medium, and short range attacks. Have perhaps three long range, four medium, and three short attacks. Make sure you are equipped with enough defense skills, especially low cost skills that you can use to block attacks that do not cause damage (such as Erase Skills). Finally, make one of your two classes the Nature class so that you can use healing skills like Healing Water.
If you are trying to move around and still want to see the enemy but do not want to lock on, press White. Their names will appear, but you will not lock onto anyone. This is a good way to keep track of your opponents but retain the freedom of moving the camera. Note: Always lock on to someone before trying to launch a defense skill unless it auto launches.