You know, he used to be as big as the Chrysler Building. You're probably thinking that this was natural for most celestial beings, but it wasn't. Angels were large, of course, but not quite like Castiel. He was always a bit taller than them. Some would think that this would make him more imposing, but it just made him more awkward. Castiel had always been the painfully uncomfortable angel. Always saying things with as much bluntness as old kitchen utensils.
It was almost endearing to some. Wings like willow branches hang around him much like his trench coat does in his human vessel. Black like man's heart and the night sky and piano keys, Castiel's wings were beautiful. At first it was an anomaly, angels normally didn't have such dark wings. They were always light colored and close the beings form. His brothers and sisters would always tease him though, no matter how mesmerizing they were. He was always the angel with the big wings and the even bigger heart.
They should have known then what he was destined for. You see, it was very clear that Castiel would fall. Not because of his wing color or the fact that he was excruciatingly truthfully, but because of his enormous heart. Castiel had always loved the humans. From day one, Father told us our commandment: love the humans. Castiel would sit for hours watching them. He was enthralled by them. Very patiently he sat, observing and understanding, waiting for an opportunity to encounter them.
The minute—no, second—that Cas touched soul, he was lost. Seeing every nook and cranny of darkness and light in a person, it changes you. You see, someone once said that you would probably fall in love with yourself if you could see yourself from an outside perspective. Castiel saw that Dean snores a little in his few precious hours of sleep. That he makes sure to give Sam the firmer pillows because they help his neck aches. That he always hums along to Fleet Foxes, even though he tells Sam that they're a girl band.
Chuck always knew Cas's destiny though. Created him special made for the Winchesters. They're very own guardian angel and quasi-brother. He knew that Castiel and Dean would eventually fall for one and other. Though this time, the descent would not be nearly as painful as the ones that they had experienced in the past. Finally Sam would have a true friend, someone who couldn't be possessed by demons or burnt to a ceiling. Some people would say that a fallen Castiel would be a broken Castiel, but I'd like to think quite the opposite. A fallen Castiel would be like finishing a puzzle that you haven't yet seen the box's picture: the completion of the bigger picture.