The Story of Sam Winchester will always be linked to Lucifer. Sam Winchester is the one perfect vessel of Lucifer. The apocalypse was supposed to happen when Lucifer and Michael would engage in a battle while possessing the Winchesters. Jared Padalecki played Lucifer in Season 5 finale episode ‘Swan Song’. In this episode, Sam said yes to Lucifer believing that he would be able to overpower Lucifer and could manage to trap him in the cage. Eventually when the consciousness of Sam is reawakened after seeing the toy soldier in the Impala, he defeats Sam.
In the episode ‘The End’, Dean is transported to the future where Sam has said yes to Lucifer and the alternate Dean is leading a war against this Lucifer. This Lucifer has nearly brought humanity to its extinction and has released the fatal Croatan Virus. This Lucifer looks charming, dressing in all white.
In the episode ‘Provers 17:3’, Jared not only portrayed an alternate Sam, but also portrayed an alternate archangel Lucifer. In this reality, Sam Winchester said yes to Lucifer and then the possessed Sam would end up taking the life of his brother Dean. Sam experiences the visions of this alternate, it is one of the endings that Chuck had in mind for the Winchesters.
Gadreel is the angel who allowed Lucifer into the Garden thus leading to the birth of evil which eventually created hell. As a result, he was locked away in a prison for a very long time. But when Metatron caused the fall of the angels, he escaped and posed as the angel Ezekiel. He tricked Dean Winchester in letting him possess Sam Winchester in order to heal him. Gadreel’s antics resulted in the demise of Kevin Tran. In the end, he would eventually sacrifice himself to give Castiel a fighting chance who could stop Metatron and save the entire heaven.
In Season 5 Episode ‘Swap Meat’, Gary Frankle, a teenager witch who comes to know about the bounty placed on the head of Dean Winchester. He along with his friends managed to hold Sam down while Gary switches the body with Sam. While being in the body of Sam, he goes on several adventures. In the end, after realizing his mistake, he trades his original body back with Sam. The Winchesters also spare Gary in the end, instructing him not to never do the magic again.