I know Vanitas is kind of out of character but I really liked the idea so i just went with it. It's not the best i can do but oh well. here it is! Reviews are welcome but please try to be nice! It is only my first try...
Disclaimer: I don't own Kingdom Hearts or any of the characters
Vanitas scowled at the being he saw before him. What was it? What was that thing in the mirror? It stared at him with bright yellow eyes, its jet-black hair forming gravity-defying spikes. He was beginning to feel uncomfortable under its cold, merciless gaze. Was this how other people saw him? Could this really be his reflection? He sighed and bowed his head, resting a hand on the mirror.
"What am I?" he whispered to himself.
In response, a million different voices in his head all uttered the same words: darkness. Pure darkness. Was that really all he was? Just a nightmare lurking in the shadows? Yes. Of course it was. How could he have ever thought otherwise? No one cared about him, not even his master.
Vanitas slowly lifted his head, once again meeting the gaze of his reflection. He was disgusted by his own image. His hands balled into fists as he continued to stare at the mirror. The growing anger inside him was blurring the lines between reality and his imagination. All he saw was the figure in the mirror sneering at him.
"You're pathetic!" it spat. "You disgust me. You're not even human! You're a thing. A worthless, despicable thing."
"Shut up," Vanitas said, but the creature only smirked as it continued.
"What are you even doing here? It's not like your master actually cares about you. He despises you! Everyone despises you!"
"I said shut up!" he shouted, his keyblade appearing in his hand.
"How does it feel? How does it feel to be completely alone?"
Vanitas couldn't take it any longer. With one fluid motion, he brought his weapon down on the mirror. It shattered instantly, causing the reflection to vanish. However, its words lingered in Vanitas' mind for days. The haunting fact that whatever he did, however hard he tried, he would always be alone. No one would ever care about him. He would always be an outsider. A monster. A thing.