Sorry if this is crap, I wrote it in like 15 minutes... Just posted it because I wanted to get it out.
Takes place at the end of KH2 during the fight with Xemnas.
Xemnas' Ethereal Blades flared; a flash of red and Riku was pushed out of the way. He knew it only could have been one person, but he found himself wishing- no, hoping- that it was somehow anyone else.
Whipping his silver hair out of his eyes, Riku could only stare in mute horror as his friend was stabbed in the chest.
Xemnas pulled Interdiction out of Sora; they were stained an deep red. More blood oozed out of the hole in the Keyblade bearer's chest.
The leader of Organization XII stepped back from the bloodied and mangled body with a smug look on his face. His orange eyes glared at Riku, daring him to do something.
So he did. Grabbing the slowly fading Keyblade from Sora's hand, he took it and Way to Dawn in either hand and leaped in the air, stabbing Xemnas with as much rage and hatred as he could muster. A look of shock crossed the man's face, and he faded away.
Blinking tears from his turquoise eyes, Riku knelt next to his friend. Both Keyblades clattered to the ground as he saw the state the younger teen was in.
Riku already knew it was too late when he saw the hole in Sora's chest. But his friend's eyes were still open and focused on the silver-haired teen.
Sora looked up at his friend kneeling over him. The brunette smiled weakly, and with his last breath, said one simple sentence:
"Don't ever forget." Then his blazing blue eyes unfocused as his heart- the heart that had saved countless others- stopped beating. His smile faded.
The Keyblade on the ground next to Riku's left knee- Sora's Keyblade- glowed white and disappeared for the last time.
All you need is the right key. Riku blinked as the words echoed through his mind. He didn't know how long he had been sitting there, staring into Sora's empty blue eyes. He reached out his hand to close them. He almost didn't want to, as if closing them was admitting he was never going to see those brilliant blue eyes again.
Darkness he hadn't felt in a long time flared up inside of him, and he stuck out his hand, opening a portal into the dark realm. Standing, he gathered up his friend's body and stumbled toward the portal.
He didn't make it though; it felt like creating it has used up nearly all of his strength. Riku had managed to walk for a few steps, but collapsed, Sora's body laid out next to him.
The silver-haired teen landed heavily on his stomach, not even bothering to stick out a hand to break his fall. He turned his head to the side, looking at Sora's face; he looked so peaceful. Riku could literally feel his heart break from sadness, and tears welled up in his eyes.
Don't worry, Sora, I won't forget, Riku thought as a wave of black swept over him.
The tears continued to flow long after he died.
Make of it what you will.