User blog comment:Twilight Despair 5/Hell Trial Theories/@comment-82.34.210.166-20130402041219

I always thought they could have used the Horsemen rings, to send the cage into Purgatory, via a portal or killing a leviathon, on the place where the cage is located in the real world. Since lucifer created demons, the cage and himself being thrown in would mean that the demons would be draged  in as well, letting demons get eaten by the souls of monsters.

The cage in purgatory  would ensure no appocalypse unless something big and powerful reordered the universe.

When castiel mentioned needing hell to maintain the cage, That made me think they were linked fundermentally with each other. Also, since lucifer likely draws power from thhe demons and the souls in hell, them being eaten and hunted for all eternity means he would be weakened. Also, if the cage ever did open, he would have to deal with leviathons trying to eat him.