Required boss fights... Zeromus in the Hardtype (or PSX) version. You need to have Edge steal Dark Matter off him so Big Bang doesn't do insane damage to your whole party. Edge is a better Ninja than a theif and he's a lousy ninja... course leveling to 99 could allow you to not have to worry about this but I have a life...

Optional bosses...Ozma if only cause there is no way to counter mini and its not fair Meteor does as much damage to you as it does to your enemies... I feel the battle is based more on luck than skill...