Another common theme is the power of love to overcome obstacles. Whether it's supernatural threats or internal struggles within the characters themselves, the love between Dean and Castiel, and Sam and Gabriel is often depicted as a force that can break through barriers. This can range from fighting against angels or demons who oppose their relationships to the characters themselves getting over their own insecurities and doubts.
One common theme is the exploration of forbidden love. Both Destiel (Dean and Castiel) and Sabriel (Sam and Gabriel) relationships often go against some sort of 'rules' in the Supernatural world. Another theme is sacrifice. Characters are often willing to sacrifice a great deal for their loved ones in these fanfictions.
I really like the Sabriel fanfic 'Gabriel's Return'. It has a great story line that involves Gabriel coming back to Sam in a very unexpected way. Regarding Destiel, 'Heavenly Bonds' is a great choice. It goes into detail about the spiritual connection between Dean and Castiel, and how it impacts their actions and decisions in the Supernatural world.
One common theme is the idea of redemption. Gabriel often has a past full of misdeeds in the Supernatural lore, and in fanfiction, Sam can be the catalyst for his redemption. For example, in many stories, Sam's unwavering belief in the good in Gabriel helps him turn over a new leaf.
One great destiel and sabriel fanfiction is 'The Unlikely Bonds' on Archive of Our Own. It weaves a story where Dean and Castiel's relationship develops alongside Sam and Gabriel's in a really interesting way, with a lot of action and emotional moments.
You can start by looking on Archive of Our Own (AO3). It has a vast collection of Supernatural fanfiction, including many great Sabriel and Destiel ones. Just use the search function and type in the relevant tags.
One common theme is the exploration of their relationship. The pregnancy often serves as a catalyst to deepen the bond between Dean and Castiel. It forces them to communicate more openly and face their feelings for each other.
One common theme is the alteration of the timeline. Since they are time traveling, any small action can change the future, and often the fanfictions explore how Dean and Castiel deal with these changes. Another theme is self - discovery. Through traveling to different times, they learn more about themselves and their relationship.
One common theme is the vulnerability of Castiel. When he's hurt, it shows a side of him that's not often seen - his fragility. It makes the readers feel more sympathetic towards him.
There's also the theme of toys coming to life in a way related to the Supernatural elements of the show. Maybe a toy becomes possessed and Dean and Castiel have to deal with it together, which could lead to some interesting character development and relationship building between them.
One popular Sabriel fanfiction could be 'A Meeting of Souls'. It beautifully weaves a story where Sabriel and Gabriel interact in a very different, more intimate setting than in the original works. Another might be 'Sabriel's Quest', which takes them on an adventure full of magic and self - discovery. And there's also 'The Bond of Sabriel and Gabriel', which focuses on the deep emotional bond that can develop between them.
Well, one unique feature is the combination of different universes. For example, when it crosses over with something like Doctor Who, you get time - traveling elements added to Destiel's story. Another is the new character interactions. When Destiel characters meet those from other shows or universes, it creates fresh and unexpected relationships.