Introduced in Season 4 for a handful of episodes, the character of Castiel won the hearts of many Supernatural fans right from the start and consequently, the showrunners had to keep him for 12 more seasons. He arguably had the most dramatic character development in the dark fantasy drama.

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Everyone's favorite angel, Castiel, is nicknamed 'Cas' by Dean, which was the first attempt at humanizing the angel of the Lord. Since then, Cas has only grown more and more human through the series. Being the third lead of the show, there are several Castiel-centric episodes, and Reddit users discuss the best of them.

The Rapture (S4, E20)

Sam and Dean talk to Jimmy Novak after Castiel leaves his vessel to go to heaven in Supernatural

The Rapture is one of the most underrated episodes of Supernatural, but it is simply amazing from the beginning to the end. The episode tells the story of how Castiel first took hold of his vessel, Jimmy Novak. A Reddit user, kh-38, says "The Rapture" is another good one, but that's more about Jimmy than Cas."

The episode holds a lot more meaning now than it did back then. After seeing Cas' transformation into an almost-human fallen angel, the angel who used another person's body and life in the episode for his own 'Godly' mission seems like another person. The episode makes the change in Castiel and how far he fell for humanity feel acute.

Gimme Shelter (S15, E15)

The end of season 15 may have been controversial in the Supernatural fandom due to Castiel's absence but the season had a lot of great Castiel moments. One such moment came in episode 15, "Gimme Shelter". A Reddit user, PSofSuddenlyGivingaS, named the episode as one of the best Castiel episodes.

Cas gives a heartfelt monologue in the episode telling about how he found a family on earth and how it changed him for the better. It provides a summary of Castiel's character transformation in his own words and that is why it pulled at the heartstrings of every Cas fan.

Hunteri Heroici (S8, E8)

Castiel Dean Hunter Heroici Supernatural

Supernatural has never shied away from outrageous episodes and one of them is episode 8 from season 8 called "Hunteri Heroici." It was a Monster-Of-The-Week episode involving murders mirroring cartoon deaths. A Redditor, ReaganGaming, comments, "I love Cas in Hunteri Heroici; it was a great and funny episode."

The episode follows Cas in the new chapter of his life that is, becoming a hunter like Sam and Dean. When Cas declares proudly that he is going to be a hunter, his childlike expression is extremely adorable and amusing.

Heaven Can't Wait (S9, E6)

Image of Dean and Castiel as Steve in Supernatural

Season 9 saw Cas becoming human and learning their ways. After Dean kicks him out of the bunker and is homeless for a while, Castiel gets a job at a Gas-N-Sip and tries to live a normal human life in "Heaven Can't Wait".

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Season 9, Episode 6 is termed the best Castiel episode by a Redditor, Asha_Brea. The episode sees Dean checking up on Cas to see if he is okay and trying to be the best friend that Cas needed in his life at that time and their chemistry is simply outstanding. Also, seeing Cas attempting to fit evokes affection and sympathy towards him.

Free To Be You And Me (S5, E3)

Castiel and Dean in Free To Be You and Me Cropped

Season 5 had a lot of great episodes with Castiel as he was still discovering how to serve humanity in the best way possible. In the third episode of the season, "Free To Be You and Me," viewers get to witness the fiery chemistry between Castiel and Dean in full force.

In the words of a Reddit user, the episode is a "great early Cas! episode" and it is one of their "personal favorites". Dean and Cas complement each other spectacularly as they team up together to find Raphael. One of the funniest scenes is when Dean takes Castiel to a brothel and Cas is freaking out the entire time, which can be interpreted as an early hint to his homosexuality.

Goodbye Stranger (S8, E17)

Castiel and Meg in Goodbye Stranger

According to a Castiel fan on Reddit, "Season 8 has some great Cas flavored angst episodes like Goodbye Stranger in which Cas and Dean have the famous fight in the crypt while Naomi pries into his mind and tries to get him to kill Dean."

Season 8, Episode 17 is a memorable episode for Destiel fans because of how Castiel can break away from Naomi's control instead of hurting Dean. It is a testament to his strength and also to Cas' love for Dean that he cannot come to kill him even when mind-controlled.

My Bloody Valentine (S5, E14)

Another excellent Castiel episode from Season 5 is episode 14 "My Bloody Valentine." The first half of the episode has some great funny moments with the Cupid and the second half is incredibly dark with the presence of one of the Four Horsemen, Famine. Castiel develops an insatiable hunger for red meat.

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A Reddit user, ReaganGaming, tells what do they feel about the episode, "When I first watched it I loved it but also found it curious how Cas was affected by Famine's power considering he's an angel'.

Lily Sunder Has Some Regrets (S12, E10)

Sam, Dean, and Castiel in Lily Sunder Has Some Regrets Supernatural

Fans always love to know more about Castiel's past. In episode 10 in season 12, "Lily Sunder Has Some Regrets," audiences witness another angel, Ishim who was a commander of a flight of angels that Cas served under, a long time ago. A Reddit user talks about the episode saying it "offers a great view into Cas' life before he started following Sam and Dean (and introduces Ishim, his high school bully).

This allowed fans to see Cas in a female vessel for the first time and explore how much Castiel has changed after meeting the Winchesters. Ishim also points this out when he goes to kill Dean to cure Cas of his "human weakness".

Stuck In The Middle (With You) (S12, E12)

Stuck In the Middle With You and Me Castiel and The Winchesters in the forest

Season 12 gave some brilliant back-to-back episodes with "Lily Sunder Has Some Regrets" (12x10), "Regarding Dean" (12x11), and "Stuck in the Middle (With You)" (12x12). While episode 10 provides a glimpse into Castiel's past, episode 12, explores his present loyalties and affections. The episode sees Cas almost sacrificing himself to save the Winchesters and he openly expresses how much they mean to him.

A fan on Reddit names this episode one of the best Castiel episodes because it has "Cas almost dying and telling his family he loves them after the BMoL [British Men of Letters] send Mary on a mission to steal a box from Ramiel, Prince of Hell."

The Man Who Would Be King (S6, E21)

Castiel in The Man Who Would Be King SPN

In the Reddit thread for best Castiel episodes, most users have mentioned season 6 episode 21. The episode is beloved among Cas fans and rightly so because it's the only episode in the entire series told from Castiel's point-of-view. Reddit user, Turks_McGurk, says that they think "The Man Who Would Be King" is the best Castiel-centric episode and the user, kh-38, also mentions it. The fourth-wall-breaking is powerful here as Cas looks into the camera and tells his story, which feels like he is explaining his questionable actions to his fans and making them understand his motives.

There are several exceptional scenes in the episode including when Cas stands next to Dean being invisible and looks at the only man who is blindly trusting him against his every instinct and when the brothers and Bobby trap Cas inside the ring of fire and they finally confront him. The emotions in this episode were excruciatingly high, especially for Dean and Cas.

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