Oh dear, I know right? What Cas did was hella rad and I don’t know why people don’t speak about it more. He went to Hell, he fought his way through the Cage, he grabbed Sam, took him away from two furious super-powerful Archangels and bring him back on Earth. No wonder he lost Sam’s soul in the process… :/ What Cas did was brave, unfortunately not enough, but brave nonetheless. And he did it not because he wanted to show-off or appease Dean’s pain. He cares about Dean’s sorrow of course and he probably wanted both brothers to be happy together but I’m pretty sure the main reason he decided to go was the danger Sam was into more than the distress of his brother. He saved Sam because he didn’t want him to rot in Hell. It’s that simple. He did it out of love because Cas cares about Sam, as much as he care about Dean.
Castiel loves his Winchesters. :)
There was a fanart about that, a funny one, somewhere on Tumblr. I need to reblog it here. I know the old sastiel shippers know what I’m talking about. :D
edit: here it is! :D