User blog comment:Markra/the episode "Reading is fundemental" 2 more archangels wtf?/@comment-4011543-20120417202126/@comment-3481504-20120417235932

That IS true, but not all that likely. See, the combination of Michael and Lucifer would end the show, as they would destroy the Earth.

With Lucifer on the Earth, along with Michael, and Crowley didn't want Lucifer there, what could he possibly do about it? He'd just have to suck it up. His appearance in Season 7 is purely imaginary, nothing else, also Cas said that if Lucifer had escaped the cage, everyone would have felt it.

1) When Lucifer stabbed Bobby, he didn't get hurt.

2) When Lucifer chucked the stake through the windshield, it didn't break.

3) When Lucifer blew the salt, it didn't really move.

Thus, he's still in the Cage, and just a hallucination.