Valor - It was great in strength and combos but you couldn't do magic. If you didn't have an item you would die in this form which sucks.
Wisdom - Great in magic but sucked horribly in strength. Plus it got annoying just shooting its magical bullets and skating against the ground.
Master = The BEST Form. It's excellent in strength, combos, and magic. It gets the job done. I can't even think of any negatives for it because it's so good.
Final - Second to Master obviously. The gliding/flying is annoying especially if you're in an open area or being timed.
Anti - Same as Valor
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The majority of you phail. "ZOMG!1!1 FINAL FORM ROX!1!1!!" Why? You don;t even give a real reason. And who cares if it has 2 keyblades? Valor and Master do too. It's only as powerful as the keyblades you give it so Master or Valor could be stronger.