Quote Originally Posted by masamune1600
The mechanics of that particular fight dictate that Cloud automatically win. If one hesitates or Row Changes or Defends, Sephiroth will have the opportunity to attack. His attack will deal critical damage (reducing HP to yellow levels), but will never actually reduce it to 0. Cloud will immediately counter (regardless of what materia he had; in fact, based on the facts that Magic, Summon, etc. commands have been removed, and artificial statistical augmentation via HP Plus, etc. has disappeared, it should be assumed that all materia have been removed), and this counter will defeat Sephiroth, regardless of how much or how little damage it inflicts. This win is, of course, automatic, since this final duel is not a physical battle. Rather, it shows Cloud finally and fully casting off the malignant force of Sephiroth's will.
couldnt have said it any better. the battle is just sort of like a playable cut scene.