"Dean, eldest prince of the demon kingdom, was on his way to the training yard outside, as he moved through the castle walls, he heard the familiar voice of Lucifer. He was incharge of dealing with new hostages, and taking them to the servant quarters deep below the surface of the earth. Just as he expected, as he rounded the corner, there was the blond haired man, leading a row of chained angels. There were about six, an impressive number. Only one dared to look up at him, it was only for a fraction of a second, but Dean hadn't missed it. It was a young boy, about his own age, he had dark black hair, and in contrast, stunning blue eyes that still shone even beneath all the dirt and grime."
"Castiel, you must watch over the child. Make sure they do not go down the darkened path. Be a shame if the child did."
"I will immediately."
The first threw her hand up. "Wait!" Castiel paused and looked back. "Come watch. The child isn't in need of our assistance yet. But soon will be."
So Castile stood beside her once more, and watched over the child.
"I think it to be beneficial that you take the child to the Winchester brothers when it is ready. This child will be good to pair with them."
Castiel nodded, knowing she was correct. But first he'd have to gain the brothers' trust more.
The very existence of the child broke many rules. But the older angel and Castiel knew God had something up his sleeve with this one. He had let the child live, and gave her the power to hide from most Angles.
And so he watched as the child grew. He watched as the child lost her mother.
He was there when the child needed someone to look after her. Most importantly, he was there when she needed a friend.
He knew Eden had a long way to go. He also knew that she would learn more alongside two brothers.
The Winchesters.
[Under editing, along with the rest of the series and a few other books. May not happen quickly, and only a few changes may be made.. Just bare with me everyone]