Perhaps in the fanfiction, the Patronus could interact with the magical elements of the courtroom. The courtroom might have enchanted objects or spells, and the Patronus could either be affected by them or affect them. For example, if there are truth - detecting spells, the Patronus could enhance or interfere with them, depending on the nature of the story.
In this type of fanfiction, the Patronus could also be a link to the past. Maybe it reveals memories that are relevant to the case. If Harry's Patronus is a stag, it could show memories of his father or other important events that prove his innocence or give context to the situation in the courtroom. This could add a lot of depth and mystery to the story.
One possible fanfiction could be where Harry has to conjure his Patronus in the courtroom to prove his innocence. Maybe he's wrongly accused of using dark magic, and the Patronus is the only way to show his pure intentions.
It might imply that the story in the fanfiction is deeply connected to the magic of a Patronus. For example, it could be about a character's journey to discover their Patronus, or how a Patronus can be used in ways not thought of before. Fanfiction often takes an existing concept and expands on it, and in this case, the Patronus seems to be that central concept. The nature of the fanfiction could be very magical and exploratory, delving into the more mysterious aspects of the Patronus magic.
A unicorn Patronus is another special one. Unicorns are known for their purity and magic. In fanfiction, a character with a unicorn Patronus might be pure of heart and have a deep connection to the more innocent and natural aspects of magic. They could be more in tune with the forest and the magical creatures that live there, and perhaps have the ability to heal or soothe others with their magic.
A Basilisk Patronus could play a key role in a mystery plot. Suppose there are strange disappearances in Hogwarts, and the character with the Basilisk Patronus discovers that the disappearances are related to an ancient curse involving snakes. Their Patronus could help them communicate with the snakes involved, leading to the discovery of the cause of the disappearances and a way to break the curse.
One common theme is justice. Fanfics often explore how justice is served or not served in the wizarding courtroom. Another is the power struggle. Different characters may try to use their influence to sway the court's decision. And of course, there's the theme of truth - finding out the real truth behind the cases presented in the courtroom.
I've read a fanfic where the main character has a fox patronus and they use it to explore the Forbidden Forest. It was really exciting as they discovered new magical creatures with the help of their patronus's senses.
In some Harry Potter fanfictions with a fox patronus, the author might explore the symbolism of the fox. The fox is often seen as clever and sly in muggle folklore, so perhaps in the fanfic, the character with the fox patronus uses these traits to outwit dark wizards or solve mysteries within Hogwarts. For example, they could use their fox - like cleverness to figure out the secrets of the Chamber of Secrets in a new and different way than what was shown in the original books.
A pegasus Patronus is also a great concept in fanfiction. Pegasus represents grace and freedom. A character with a pegasus Patronus might be someone who values these qualities. They could be the type of person who is always looking for a way to break free from constraints, whether it's social norms or dark magic threats in the wizarding world. This Patronus could also suggest a connection to the skies and a more spiritual side of magic.
One common theme is identity. Since having a snake patronus is often associated with Slytherin and dark magic in the original series, characters in the fanfiction often struggle with how this patronus defines them. Are they really different from the 'good' Gryffindors? Another theme is secrecy. A snake patronus can be seen as something to hide, so there's often a plot around keeping it a secret or the consequences of it being revealed.
In certain fanfictions, a Patronus can be used to enter a character's mind. It's like a bridge between the conscious and subconscious. This allows for some really deep exploration of a character's thoughts and memories. For example, a character might send their Patronus into another's mind to help them overcome a mental block or a hidden fear.