Changes

* [[Nick]] assents to Lucifer near the end of [[5.01 Sympathy for the Devil]]. He serves as a vessel for Lucifer until Sam will consent to be the vessel<ref>[[5.22 Swan Song]]</ref>. Castiel says that Nick must be drinking gallons of [[demon blood]] to remain intact, and Lucifer himself notes that Nick is wearing a bit thin.<ref name="five21">[[5.21 Two Minutes to Midnight]]</ref> Some years after Lucifer was trapped in the Cage, Crowley was able to retrieve Nick and perform various rituals on him so that he would serve as both a permanent vessel for Lucifer after his apparent banishment<ref name="twelve13"/> and a means of torturing Lucifer, runes and spell-work from the Cage carved into every molecule of Nick's form to enable Crowley's torture and render Lucifer powerless and unable to vacate his vessel<ref>[[12.15 Somewhere Between Heaven and Hell]]</ref>. It took a team of twelve demons to perform these rituals, with Crowley killing all of them after the work was over so that none of them could help Lucifer escape<ref name="twelve17"/>, but Lucifer, with the aid of the demon [[Drexel]], was eventually able to turn the security system against Crowley, allowing him to break free of its chains.<ref>[[12.21 There's Something About Mary]]</ref>

* [[John Winchester]] assents to Michael to save his wife from [[Anna]], with Michael assuring Dean that he will protect John from experiencing too much damage during his time as Michael's vessel.<ref name="five13" />