User blog comment:Victory awaits/The actual outcome of Apocalypse?/@comment-26982641-20161001101547/@comment-1975828-20161001220131

Some of things Castiel said during season 5 contrast a couple of pre-established facts. I feel as though half the things he said were merely for suspense. Also, some of his statements seem to be forgotten, like Sam's need for demon blood to house Lucifer. There was no mention of it prior to that and not after.

So, I wouldn't rely on what Castiel said much. His words became confusing during that season, not all of them, but some.