the nightmare mask- the abitiy to walk by enemies without them attacking you. your defense, attack and speed is raised. certian areas will allow you to teleport with this mask on. you can go through some objects. and in certian parts of the game you can go into people's dreams and fix them so they wake up and give you answers, or corupt them so they get out of you way in order to get peices of heart, the instrument you play with it on is guitar and the song goes- ^,v,<,>,A. the only draw back is that is SLOWLY takes away magic Ex. after 5 minutes of wearing it, one little bar of your magic (as wide as the pixles on your screen) goes down. now in order to get it you must have all heart containors, all the upgrades (wallet, poes, bugs, whatever) magic doubled, and the strongest sword, then you talk to the person who gives you the oringonal sword and fight them, once you beat that really hard battle, you use this pendant they give you to open this door of pure darkness and go inside to claim this mask, phew that was a lot