A lot of Castiel hurt fanfictions explore the theme of sacrifice. Castiel might get hurt while trying to save Dean or Sam or in the process of protecting humanity. His self - sacrifice and the resulting pain are often delved into. There's also the theme of isolation when he's hurt. He might isolate himself to heal or because he doesn't want to burden others, and this can lead to some interesting character development.
The theme of Castiel being tortured, either physically or mentally, is quite prevalent. It could be at the hands of demons or other angels. And then there's the aftermath of his hurt, like his struggle to regain his strength or his faith. Also, his relationship with Dean often takes center stage during his time of hurt, with themes of Dean's protectiveness and Castiel's dependence on him.
One common theme is redemption. When Castiel is hurt, often the story will revolve around him finding a way to redeem himself, whether it's from a mistake he made that led to his pain or just from a sense of lost purpose. For example, in some fanfictions, he might have been hurt because he trusted the wrong entity and then has to make amends.
One common theme is isolation. Castiel often feels alone in his pain, whether it's due to his otherworldly nature or the actions of those around him. Another theme is betrayal. He is frequently betrayed in these stories, which causes him deep emotional harm. For example, when his allies turn on him or when he is misled by false friends.
One common theme is loyalty. Gabriel's protectiveness shows his loyalty to Castiel. Another theme is sacrifice. Gabriel might be willing to sacrifice his own well - being or position to keep Castiel safe. For example, he could risk getting on the wrong side of other powerful angels.
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.
A common theme is the exploration of Castiel's humanity. When he's being protective of the hurt Dean, he starts to understand human emotions like love, fear, and worry on a deeper level. This can lead to his own character development as he becomes more in tune with his human side while still maintaining his angelic essence.
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.
One common theme is Castiel's struggle with his angelic nature and his growing humanity. He often has to choose between following angelic orders and doing what he believes is right. Another theme is his loyalty to the Winchesters, especially Dean. His relationship with Dean is a central focus in many fanfics, whether it's a deep friendship or something more. Also, themes of redemption are common, as Castiel has made many mistakes in the series and fanfics often explore his path to redemption.
One common theme is friendship. Their bond, whether it's a platonic friendship or something more, is often explored. Writers like to show how they support each other through tough times.
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 common theme is identity. Since Castiel is usually male in the original series, when she's female in fanfiction, there's a lot of exploration about how she sees herself and how others perceive her. For example, some fics show her struggling with the new body and the expectations that come with it.