As we left season Season 7 has this awesome opening in which Castiel assumes his new role as God, Castiel sets out to right some of the wrongs in the world. he Winchesters summon Crowley in exchange for a spell to bind Death, they summon him but Death is not pleased, Dean orders him to stop Castiel, but the former angel is one step ahead of them, leaving Dean to face an angry Death, while Sam struggles to deal with the broken wall in his mind due to memories in the cage. Castiel appears to them, confronting the brothers and prepares to kill them. Death tells Castiel that consuming every soul in Purgatory isn’t his only problem, Death confides that he also consumed one of God’s earliest creations, “The Leviathans” – the first beasts. Castiel breaks the binding spell due to the betrayal of Dean when he tells Death to reap him.
Eventually, Castiel disappears, Death tells the brothers that he warned them about Purgatory, and he tells them to persuade Castiel to return every soul back to Purgatory. Death then leaves. Castiel awakens in a room full of massacred individuals and believes that he is too weak and finds that he cannot control the powers of the Leviathans, and goes to the brothers for help; they re-open the door and although they send most of the souls back into Purgatory, theLeviathans remain. The beasts take over Castiel’s body and claim to have killed him. Meanwhile, Sam has a vision of Lucifer, who tells Sam that he didn’t truly escape, and is still in the cage — that this is just his own ultimate torture. Sam disappears, leaving Dean and Bobby to face the new threat on their own. The Leviathans confront and attack Dean and Bobby. Their intentions on Earth are yet unknown.
The rest of the season is about the Winchesters facing a new enemy, in the Leviathans, stronger than they have encountered so far, and everything they know, as well as rendering their weapons useless. The leader of the Leviathans takes the form of Dick Roman, a powerful businessman and president of one of the largest corporates in the US with a worldwide hold over various field. Among the more memorable stand alone episodes is the one with two powerful witches played by James Marsters & Charisma Carpenter who prove to be too powerful for the brothers. Sam and Dean are framed for a series of murder-robberies by two Leviathans that take the forms of the Winchester brothers. Crowley then appears to Dick in an effort to build a partnership, but Dick harshly turns Crowley down, considering demons to be even more pathetic than humans, and hinting that he wouldn’t mind wiping them off the face of the Earth. During a raid on a Leviathan ‘s stronghold, Bobby is shot and later dies. Dean has now become obsessed about hunting Dick Roman, and leaves no stone unturned in doing so. Meanwhile Sam has hallucinations of Lucifer taunting him which affects his ability to do the job.
Lucifer has driven Sam to the point of mental breakdown, because of which he is now committed to a mental institution. Dean searches for help and is led to a healer – who turns out to be Castiel who now is living under the name Emanuel and works as a faith healer, and has no memory of his past life as an angel. Dean convinces him to come with him to heal Sam of his mental break down. Castiel later regains his memories and is torn apart by guilt. He does the next best thing: transfers Sam’s madness and experience in Hell, to himself. So while Sam is released, Castiel stays in the hospital plagued with the visions of Lucifer. Meg takes up a job in the hospital, to support Castiel, and look after him. The brothers, back on the job, find out that Bobby’s ghost is following them, attached to the living world via his old flask. They then find a prophet in the making, Kevin Tran, when an ancient table is found inside a clay encasing awaking his abilities and Castile also wakens up. The brothers must keep Kevin & his mom safe from the demons that attack him. Dick then calls for Crowley to discuss a deal; help him get the Winchesters & he will give him Canada to do as he pleases. Dean and Castiel confront Dick in the lab, but when Dean stabs him through the heart with the weapon, it fails to kill him. However, Dean reveals this to be a trick and while Castiel holds Dick in place from behind, stabs Dick through the neck with the weapon, killing him. However, Dean and Castiel disappear and Crowley betrays Sam, taking Kevin and planning to become the next major threat. Crowley also has an army of demons in the building dealing with the remaining Leviathans located there now that Dick is dead. Dean and Castiel find themselves in Purgatory surrounded by monsters and Castiel disappears on Dean.