There's also a story where Castiel kidnaps a fan in a desperate attempt to save the world. It's a complex plot that involves time travel and alternate universes. You can find it on FanFiction.net. The story really delves into Castiel's character and his motives behind the kidnapping.
A common plot is that Castiel kidnaps someone he believes is key to saving Dean or Sam. For example, in many fics, he might think a fan has some sort of special power or knowledge. Another plot is that he's being manipulated by other forces to kidnap someone, and then he has to figure out how to make it right.
One common theme is the theme of rescue. Usually, the other characters, like Dean and Sam, will go to great lengths to save Castiel. For example, they might face numerous dangerous creatures or powerful enemies in their quest to rescue him.
One great aspect of Castiel and Dean in fanfiction is their dynamic. Their relationship, which is complex in the show, can be explored even further in fanfictions. Writers often delve into their unspoken bond, creating scenarios where they support each other in ways not shown in the original series. For example, some fanfictions might have them going on a road trip together just for the sake of exploring new places and having deep conversations about their pasts and futures.
Fanfiction about Castiel in Supernatural can be really interesting. Some 'hopeless' fanfictions might focus on his often tragic or difficult situations in the show. They could explore his loyalty to Dean and Sam even when things seem truly hopeless for him. Maybe it's about his struggle with his angelic nature and the chaos of the human world he's thrown into.
A lesser - known but very interesting kidnapped Castiel fanfiction is 'Finding Castiel'. It has a unique take on the kidnapping plot, where Castiel is not only physically kidnapped but also has his memories manipulated. The way the author unfolds the mystery and the other characters' efforts to bring him back is quite engaging.
Castiel's relationship with his powers might also change. He may have to limit his use of angelic powers to protect the unborn entity. This can cause internal conflict as he is used to using his powers freely. At the same time, it can also show his growth as a character, as he is willing to sacrifice some of his power for the sake of something new and precious.
I remember reading a fanfic called 'Castiel's Wounds'. In this story, Castiel is severely injured during a battle with demons. The fic focuses on how Sam and Dean try to help him recover, and the relationship dynamics between the three are really well - written. It shows Castiel's vulnerability in a very believable way. There's also 'A World of Hurt' which explores Castiel's hurt in a post - apocalyptic setting, adding an extra layer of tension and drama.
Well, 'The Road Less Traveled' is a popular 'Supernatural Dean and Castiel fanfiction'. It's set in a post - apocalyptic world where they have to rely on each other more than ever. It has great character development and some really intense scenes. There's also 'Soulmates in the Shadows' which plays with the idea of them being soulmates in a unique way.
One common theme is redemption. Since Castiel has made some mistakes in the show, a lot of fanfiction focuses on him trying to make up for those. Another theme is his relationship with the other main characters, like Dean and Sam. His loyalty and how it is tested is often explored.