Alright, I'll admit something right off the bat: I suck at writing normal stories. I just like thinking up random fight scenes while listening to music.
Characters: Sora, Vanitas, and Master Xehanort (barely)
Song: Handlebars by Flobot
Sora stands facing a masked figure. Behind him is a haze filled with hearts. These hearts are the connections between all of those he has fought alongside. The figure is wearing the same kind of suit Riku did while he was under the influence of darkness. Without a word, both of the combatants launched themselves forward. There's a clash of keyblade and they break apart. Sora gazes in surprise at Vanitas's keyblade. "Why do you have one!?" Unseen by either of the combatants, Sora's shadow screams.
Vanitas does not answer. Instead, he raises one hand. Frost dances across his hand and launches itself at Sora. The hearts behind him blaze brightly and the frost is dissipated by the slash of two keyblades. Sora's costume has become a bright red. He now holds two keyblades, one black and one white. Their contrast is striking. The figure waits as Sora charges. Sora brings both keyblades around in a sideways sweep. Vanitas blocks but suddenly is thrown aside by the strength of the attack. Sora rushes Vanitas who is forced to constantly block and move aside.
Sora cracks his neck and throws both keyblades into the air where they fuse into one. His clothes begin to change color as Vanitas takes this chance to charge forward. Just as Sora catches his weapon, Vanitas runs him through. Vanitas grins under his mask, only to step backwards as the image of Sora fades. Behind him, Sora appears in a blur, his new form allowing him to shoot across the ground at intense speeds. Vanitas is hit in the back by several bolts of magic before he can dodge. He then stands his ground as Sora glides around him, firing bolts. He says "You won't catch me by surprise like that again." Sora smiles and Vanitas realizes one of the bolts was not blue but instead red. The fire spell explodes, sending Vanitas stumbling back.
Sora jumps through the flames, once again wielding two keyblades. This time, however, his clothes are yellow. He brings them both down on Vanitas, using the power of his jump to add to his attack. Vanitas holds the attack and a quick swipe sends Sora stumbling back. Vanitas fires a dark bolt of energy which Sora dodges. He lands, confused. Vanitas was pointing behind him. Sora turned and his eyes widened in terror. The bolt was weaving through the hearts behind him, causing them to go dark one by one. Sora threw Oblivion at the bolt just as it passed through the last. Sora's clothes changed back to normal and Oathkeeper disappeared as Sora's other keyblade clattered to the floor.
Sora turned back to Vanitas just as the other launched a barrage of dark blasts. Sora rolled across the floor to grab Oblivion but was unable to block the majority of the attacks. Then Vanitas was suddenly upon him. He grabbed Oblivion with one hand and slashed Sora across the chest. He turned just as Sora fell to the floor. He was walking away when he paused. "What the...?" He turned around to see an enormous amount of dark energy radiating from Sora, who was now standing. "What are you?" He ran forward and swung his keyblade at Sora.
Then he froze. Sora's hand had disappeared in a blur and had grabbed Vanitas's own keyblade, Void Gear, without any apparent effort. Vanitas pulled at his weapon but it remained firmly in Sora's loose grip. Then Sora's other hand disappeared and Vanitas was torn from his weapon by Sora's punch. He slid across the floor but launched himself up onto his feet just to see the energy envelope Sora and turn his entire body black. Sora's eyes became yellow orbs and dark energy flowed off of his body. He turned toward Vanitas and disappeared in a blur. The next thing Vanitas knew, he was being pummeled by an apparently invisible enemy. He would see Sora for one moment before the hero would disappear and another attack would hit Vanitas. In only a few minutes, Sora had pummeled Vanitas into the ground. Then Sora turned to see the master of Vanitas watching him. "You are an interesting child. I'm going to have to see what you are." Sora charged him and...
To be continued...