A Makeshift King's Finale
When he finally died for good, he was honored the same as every other human. Castiel stood watching, invisible to the humans, as Dean's body was washed, and dressed up, placed in a box of wood. The group of humans who attended the funeral was small, and, from the way Sam kept glancing around, they had expected Cas to show. Cas did not show himself, at least to them.
Castiel merely watched. Watched as the coffin was closed, lowered into the earth, and covered in flowers and dirt. How appropriate, Cas thought, that humans would choose to encase their dead in the bodies of fallen trees and lower them to rot together into the soil. So finite, this whole species and all its customs. Cas thought about how when angels died, the whole of heaven knew, because the whole of heaven felt that bright spark extinguish. Cas thought about how when angles died, nobody mourned them, because angels are soldiers, and soldiers do not show weakness (emotion, he means). Cas thought about how though Dean's body died, his soul continued to live.
This time, it would not be shoved back into his body to live again. His body had given out. Too old, Sam explained, when Cas asked. Castiel did not understand the concept of too old. Angels did not get old. He did not understand how a human could just stop working for no reason.
For the first time in his life, Castiel mourned. He sat on the grass, the sun was shining above him, wind blowing around him, it was an ideal day, but Dean was dead. Cas sat on the grass and forgot heaven for a period of time, forgot what it felt like to repress everything he felt.
When Cas remembered heaven, his chest and throat were sore, his eyes itchy, and his cheeks wet. He rose to his feet, unsteadily, and approached the grave. The sun had gone and the human mourners with it. I promise, he thought, before realizing that this was better promised aloud.
"I promise, Dean," Cas said, in a shivering voice. "I promise that wherever you are now, I will find you. I promise that in the next life and the next and the one after that, I will find you." You will not remember me, but I will remember you, Cas didn't add. He glanced up at the sky, and sighed. Cas didn't regret finding himself here, at the gravesite of his friend (who'd endured too much, maybe death was a kindness, now), but he regretted having to leave this finite, rushed world. This finite rushed world with so many reminders of all Cas could never be, and everything human he couldn't have. Like Dean, his thoughts remind him. You could never catch up to him, always so far ahead and running farther.
Castiel spread his wings, softly beating, slowly carrying him away from Earth and Dean (away from home! His thoughts scream. Don't leave!).