Use the following tactics during the battle for the 20th seed. Take out Leon first. Leon is not very difficult, considering that he and Cloud fight very much alike. When he gets near the end of his life, he powers up his sword and can reach long distances for serious damage. Cloud, on the other hand, does about three moves throughout the entire battle. After defeating Leon, heal yourself and stay out of Cloud's way. Allow Donald and Goofy to take a beating. Cloud only does his rush move about six times then does a Braver. This gives time for Donald to heal Goofy and himself to still take a little life out of Cloud. Dodge Roll frequently if Cloud decides to attack you with rushes. Whenever Cloud does a Braver, use Arcanum or just flat out beat him -- he does not attack for the period that he is taking his sword out of the ground; then, jump and glide (or dodge roll) out of his way.