Talk:Seven Deadly Sins Series/@comment-4698889-20141115231729/@comment-6192846-20141115234736

Sealing a vessel is merely a binding that can be removed. If the demon's true body is in the vessel, it is trapped there; if possessing a human, it will be unable to access it's true body's vessel, but will remain until it runs out of power, at which point it disappears from the one possessed.

Elluka sealed all the vessels she collected from Mikina, but clearly Julia recovered some of them at some point and removed the seals. They aren't permenant solutions.