With Jack stepping into the role of God, the world went back to normal — which is something, considering how far from normal we all are in 2020 — and each and every person Chuck erased came back to their old selves. But hoo golly has Season 15 done a good job of tying up loose ends!
He ended up betraying Crowley and absorbing all the souls, resulting in his powers reaching a level much higher than that of an archangel, but at a high price: the powers that the evil souls granted him had went to Castiel's head, causing him to proclaim himself as the new God.
Eileen Leahy - Sam's final love (Season 15)
That is until Chuck wiped everyone from existence (“Despair”).
Metatron (Curtis Armstrong) is looking for food on a dumpster when he is suddenly transported to a bar where he finds prophet Chuck Shurley (Rob Benedict). Chuck gives Metatron glasses and when he puts them on, angels begin singing and a stunned Metatron realizes the shining Chuck is God.
Chuck is God (and also he has a sister). In the show's 14th season, it threw another twist Chuck's way: Not only is he God, but he's been the author of Sam and Dean's lives, and when Sam (Jared Padalecki) and Dean (Jensen Ackles) decided not to follow through on Chuck's story, well, they pissed him off.
While Sam, Metatron and Donatello rescue Lucifer from Amara's hideout, Dean tries to distract her. Eventually, she discovers Dean has met God and that they're planning on freeing Lucifer from her. Metatron stays behind and tries to hold back Amara but she's too powerful for his cast and he is imploded into nothingness.
Chuck was a prophet. His name WAS on the Prophet list. He just happened to be God also, and Cas cant see God - like people cant look at an Angel's true image.
Other than that god Leviathan Castiel is weaker than chuck/god because he didn't see it as a threat to his rule or did anything to stop or defeat in they were just good stories he was writing for his favorite characters Sam and dean to combat. According to the Supernatural Wiki he becomes as powerful as Chuck.
Trivia. There has been hints by many characters that Castiel is God's favorite angel, due to his resurrections and improvements to his powers by the latter's hands. Castiel's resurrections has caused him to be known as God's chosen as he has earn the envy of many angels.
He became the meat suit for the Archangel Michael…with a twist, of course. It's not the Michael that wanted to go head-to-head with his brother, Lucifer, all those years ago. No, this is the Michael from the apocalypse world. The one who tortured our Lucifer and made his life hell on Alt!
In the end, Dean (Jensen Ackles) went out the way he always thought he would: Hunting. He was killed in the series finale while taking on a nest of vampires, but his ultimate end would come in the show's final moments, when he was reunited with Sam (Jared Padalecki) in heaven.
Supernatural Season 13 has added a new cast member whose surname will be abundantly familiar to fans. Danneel Ackles, an actress who, of course, is the wife of Dean Winchester himself, Jensen Ackles, is set to play a recurring character.
Fitting: Ended Up In Heaven
Most fans know that whenever a person dies, they either go to Heaven or Hell. Because Dean died several times in the show, it was only fitting that he not only died in the show's finale but that he was rewarded for his job as a hunter by going to Heaven.
Cassandra Masters is the daughter of Castiel and Meg Masters and the only known Nephalem to exist, which is a hybrid between a union of an angel and demon, even being part human due of Castiel and Meg's human vessels. Cassandra acts as one of the leading main characters with Sam and Dean.
"What does this sound like a goodbye?" Dean asked. "Because it is," Castiel replied. "I love you." After admitting his feelings, Cas makes the ultimate sacrifice by letting the Empty take him away — along with Billie who had just arrived — after pushing Dean out of the way.
However, he resurrects Castiel three times: to help stop The Apocalypse, apparently as a reward with greater power for helping stop the Apocalypse, and Castiel believes the last one was a punishment for his actions in declaring himself God.
Michael is the first and oldest of the four Archangels created by God, making him the very first angel ever created, as well as one of the oldest and most powerful beings in the universe.
Jack Kline (b. May 18, 2017) is the son of Lucifer and Kelly Kline. He is the first and only known Nephilim to be sired by an Archangel. Jack was taken in by Sam Winchester and Dean Winchester who would teach him how to master his powers.
Amara is the embodiment of the Darkness -- God's twin sister. God and the Darkness were previously one cosmic being composed of both light and darkness, who split apart into two separate equally powerful beings, causing the Big Bang and bringing existence into being as a result.
Strongest: Alpha Vampire
The Alpha also appeared later and even helped Sam and Dean in their fight against the Leviathans, undoubtedly making him one of the strongest, if not the strongest of his kind.
While he calls himself a new god, Death describes his appearance as that of a "mutated angel." As the leviathans start to take over within him, and his killing becomes indiscriminate, Castiel returns to Sam, Dean, and Bobby and they help him return the souls to Purgatory.
Supernatural's final season has established God as the main villain, but this major twist was teased way back in 2009 with Chuck's season 4 debut. Supernatural's final villain was first teased over a decade ago in Chuck Shurley's very first appearance.
He later goes on a suicide mission, stating that he would rather die than watch Dean crumble and fail. Dean appears visibly saddened by Castiel's lack of faith in him. Castiel later returns in Two Minutes to Midnight and apologizes to Dean for not having more faith in him. Dean forgives Cass, and they reconcile.
Dean wasn't just angry for Castiel's role in bringing the worst out of God, as his main anger came from the idea that Castiel was responsible for the death of Mary. Making things worse was when Castiel killed the traitor Belphagor, which led to Rowena having to sacrifice herself.
Chuck's solution was to create The Old Gods, which would serve a dual purpose. On one hand, the "lesser" deities could take the blame for mankind's hardships, and on the other, the new creations would make for excellent players in Chuck's ongoing narrative - the same role currently held by Sam and Dean.