One interesting 'Prince Caspian' fanfiction could be about Caspian's adventures before he met the Pevensies. Maybe it details his training as a prince and how he learned about Narnia's secrets.
The main themes include adventure. The whole story is filled with various adventures from battles to exploring new parts of Narnia. Friendship is also key. The relationship between the different characters, whether it's between the Narnians or between the Pevensie children and the Narnians, is based on friendship. And there is a theme of magic. Narnia is a magical world and the use of magic and the presence of magical creatures play an important role in the novel.
Prince Caspian is of course a very important character. He is the rightful heir to the throne of Narnia. The Pevensie children - Peter, Susan, Edmund and Lucy - are also crucial. They are summoned back to Narnia to help Caspian. Trumpkin, the dwarf, is an important character too. He is a bit grumpy but very loyal and helps the group in their adventures.
The theme of friendship and alliance is also prevalent. Hermione and Prince Caspian usually form an alliance. They work together towards a common goal, whether it's saving Narnia from a new threat or bringing about a better future for the land. Their friendship grows as they rely on each other's strengths and overcome their weaknesses.
The White Witch could make a great antagonist even in a Prince Caspian and Peter fanfiction. Her evil magic and desire for power are well - known. She could return in some form, perhaps a remnant of her magic that was left behind and has now taken on a new, more insidious form. Another option could be a power - hungry Narnian noble who wants to overthrow Prince Caspian and sees Peter as a threat to his plans. He could be sly and manipulative, causing trouble for both of them.
Another option is to check out some Narnia - related forums. Sometimes, fans share their own fanfictions on these forums or recommend good ones they've found. You can interact with other fans and get more personalized suggestions for 'Prince Caspian' fanfiction.
One idea could be that Susan returns to Narnia during a time of great peril, and she and Prince Caspian have to team up to defeat a new, powerful enemy. They might discover hidden powers within themselves along the way.
The relationship can be developed through shared adventures. For example, they could be on a mission to retrieve a lost magical artifact. During this journey, they rely on each other's skills and start to respect and admire one another more deeply.
In fanfiction, their relationship can be developed by introducing cultural exchanges. Since Prince Caspian is from Narnia and Lucy is from England, they can teach each other about their respective cultures. Lucy can introduce Caspian to things like tea - time and proper English manners, while Caspian can show Lucy the unique traditions and magic of Narnia. This exchange of knowledge and experiences can bring them closer together and create a more complex and interesting relationship.