Castiel had felt it coming since his return from Heaven. Honestly, he had felt it coming from the moment he rebelled. He knew he wouldn’t be left alone for long; he knew his brothers would not rest. Though the feeling had begun to get stronger during the past few days. He could feel the end coming, and he knew he would not last much longer. He didn’t burden anybody with this, though. Ninety percent of the people Castiel knew would have tried to find a way to stop it, and Cas knew there was no way. There was no sense in wasting time and effort — and perhaps even getting hurt — on a useless cause.
He wasn’t stupid, though. He knew they would prefer to know than to be left in the dark, he just chose to leave it until the last moment. He wondered idly, the thoughts of a dead man waiting for his end, if Chuck had prophesized his demise, though knew it was of no import. There was nothing anybody could do for him now and, he knew that. The angel had one final wish, though. And that was to spend his last moments with the people he was closest to.
That’s how he came to be where he was now, completely empty of any power and completely human. The trip here had stolen the rest of the mojo in his reserve and now he was empty. Since the angel (now ex-angel) had been anticipating this change, when it happened, he wasn’t as shocked as, perhaps, he should have been. Now that his Grace was gone, now that he was human, he was also oddly peaceful. He wondered just how long he had been ready for his end, or if it was a new thing. He supposed it didn’t really matter; he was going to die anyway.
Once his Grace was gone, his human body began to lose energy, too — and quickly. He knew that this loss of energy was not one that could be rectified by sleep. His limbs felt unnaturally heavy, and a sharp pain split through his head, though he held back the wince. There was a churning in his stomach, like it wanted to throw up, though he had nothing to actually throw up. The ex-angel could feel the sweat begin to appear on his brow and his face paled. Eventually, he decided to speak up, before it was too late. “Hello.”