User blog comment:Egyptian Hybrid/What happened to the other Leviathan?/@comment-1031724-20170421013633

As to Leviathans in Purgatory, I remember it was said that a few of them remained inside Castiel when the others were returned to Purgatory, so the Leviathans we saw on Earth in Season 7 probably weren't all of them, as they were previously imprisoned there and a lot of them possibly remained there