Question: Zachariah reveals in season 5 that it was planned all along for Lucifer to be released so Michael could battle with Lucifer in an epic showdown that could risk half the world. My question is, wouldn't it make more sense to let Dean know he's Michael's vessel and have Michael either ready to slaughter Lucifer inside the cage or, worse case, be right there ready to attack the very second Lucifer gets released so no innocents are risked?
Question: In the one episode Gabriel attempted to kill Lucifer with his archangel blade. Even though he didn't succeed, why didn't they attempt to do use one before? Couldn't Cas have given them one, or gotten one if an archangel's blade is different then an angel blade (I'm not sure), or would it have even killed Lucifer, because he is an angel after all?
Answer: Angel blades come from angels. It's their angelic magic that makes it special. Therefore, an archangel blade is made magical with the powers of an archangel. They couldn't have just created one or used one, as none of them are archangels.