This is not a cheat. Rather it is a very important hint to help players stay alive especially in Expert mode. When fighting the final dungeons or bosses nearing the end, it is avery important to summon Tinker Bell into battle. She doesn't take up any party memebers place and she constantly heals Sora, reviving him once if he is KO'd. You may say "This is total bullshit! Who doesn't know she can be summoned into battle?" Yes that's true but I tell you most people will be so engrossed in fighting that they will forget to summon. I sometimes will also forget.