A powerful patronus can be shown through its physical appearance. For example, it could be larger than normal or have a more intense glow. In some fanfictions, a powerful patronus might be able to change forms depending on the situation, like from a stag to a dragon for added strength.
Another aspect is the emotional connection. In fanfiction, a character with a powerful patronus might have an extremely deep and pure emotional wellspring from which they draw the power. This could be due to a great love, an unwavering loyalty, or a selfless sacrifice they've made or are willing to make. It makes the patronus not just a magical defense but a manifestation of the character's very soul.
In some fanfictions, a Patronus might be more powerful than in the original books. For example, it could have additional abilities like being able to communicate complex thoughts instead of just being a defensive charm. Fanfic authors often like to expand on the magic system.
In many fanfictions, Harry Potter is made into a powerful wizard by being given new and unique magical abilities. For example, he might have the power of telepathy with all magical creatures. This allows him to communicate and gain their assistance, which makes him seem very powerful. He could also be shown as having a much deeper understanding of ancient magic than in the original series, enabling him to perform feats that are considered impossible in the normal wizarding world.
There's 'Aurora of the Patronus'. It focuses on a group of young witches and wizards who, through their combined efforts and strong patronuses, fend off a dark force that threatens Hogwarts. The descriptions of the patronuses are vivid and make the story very exciting.
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.
In the fanfiction, he could master it with the help of a new mentor. This mentor might have a different approach to teaching magic compared to Dumbledore or Lupin. They could introduce Harry to some ancient magic techniques related to the Patronus Charm. For instance, they might teach him how to combine different spells with the Patronus incantation to make it more powerful. This way, Harry would be able to master the Patronus Charm in a more creative and unexpected way.
The author can describe his internal thoughts. Harry might be thinking about all the possibilities and how great things are going to be. He could be daydreaming about the upcoming event that has him excited. Also, his interactions with other characters can show his excitement. He might be talking non - stop to Hermione and Ron about what he's looking forward to.
In Harry Potter fanfiction, snakes can be given unique backstories. For instance, a snake might be the last of its kind, a species that was hunted by dark wizards for their scales which were used in powerful potions. Harry could take it upon himself to protect this snake. The snake could then repay Harry by using its ability to sense danger, warning him of approaching Death Eaters or other threats long before they are visible. This would add an interesting dynamic to the story and show snakes in a more complex and sympathetic light.
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.