One great Castiel crossover fanfiction is 'Castiel in the World of Harry Potter'. It combines the mystery of Castiel's character with the magical world of Hogwarts in an interesting way. The story explores how Castiel would interact with wizards and witches, and his attempts to understand magic, which is very different from his angelic powers.
The clash of different universes is really interesting. For instance, when Castiel is put into a world like Middle - earth from Lord of the Rings, his angelic nature stands out so much against the more earthly magic and races there.
You can start by looking on fanfiction websites like Archive of Our Own (AO3) or FanFiction.net. Just type 'Castiel crossover' in the search bar, and you'll get a whole list of stories. AO3 has a great tagging system, so you can also filter by the specific fandom you want Castiel to cross over with, like Supernatural and another show or movie you like.
One great Supernatural Castiel crossover fanfiction is 'Castiel in the World of Harry Potter'. It has an interesting plot where Castiel finds himself in Hogwarts and has to deal with the magical world while still being an angel. It's really exciting to see how he interacts with the characters there.
Yes, there are likely some Naruto and Castiel fanfictions out there. Fanfiction writers often like to combine different fandoms in creative ways. You can try searching on popular fanfiction websites like Archive of Our Own or FanFiction.net to find such works.
A bit. Given that he is part of the 'official' narrative, fanfiction can be really out - there. It might seem odd to him that fans have taken his character and put it in all sorts of situations that may not be in line with what he knows. However, he might also find it interesting to see the different perspectives on his character.
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.
Another excellent fanfiction is 'Heaven's Gatekeepers'. This one plays with the idea of their roles in the grand scheme of things in the Supernatural universe. It has a great plot that weaves in and out of canon events, and the way it portrays Dean and Castiel's connection is both unique and captivating.
One great 'Castiel and Reader Fanfiction' is 'Heavenly Bonds'. It beautifully depicts the relationship between Castiel and the reader with a lot of emotional depth. Another one is 'Angelic Encounters' which has some really interesting plot twists. 'Castiel's Devotion' is also a popular choice as it shows Castiel's unwavering loyalty to the reader in various challenging situations.
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.