The theme of secrecy is quite prevalent. Just like in the original Harry Potter series where he had to keep his wizarding world a secret from muggles, in werewolf Harry fanfic, he often has to hide his werewolf nature. Also, the theme of power and control is common. Harry has to learn to control his werewolf powers which can be both a strength and a danger.
Friendship is also a big theme. Harry's friends play an important role in many of these fanfics. They might help him hide his werewolf identity, or they could be the ones to encourage him to embrace it. Their friendship is tested and strengthened through the werewolf - related events in the story.
One common theme is the struggle against prejudice. Werewolves in the Harry Potter universe are often discriminated against, and fanfics usually explore how they deal with that. For example, they might fight for equal rights within Hogwarts or the wizarding world at large.
Another theme is the struggle between the human and the wolf side. Werewolves have to constantly battle with their wolf instincts. Fanfics often detail how characters like Remus Lupin try to maintain their humanity while dealing with the monthly transformations, and how this affects their relationships with other characters.
Well, a major theme is struggle. Harry struggles with the new instincts and limitations that come with being a werewolf. Another theme is relationships. His relationships with Ron, Hermione, and other characters are often re - examined in these fanfictions. And there's the theme of power. How does being a werewolf change his power dynamics in the wizarding world? Does it make him stronger or weaker in different ways?
Romance is a very common theme. Werewolves often fall in love with humans or other supernatural beings. Another theme is loyalty, as werewolves are usually very loyal to their pack. Also, the struggle between their animal instincts and their human side is often explored.
One common theme is leadership. The alpha werewolf often has to lead his pack through various difficulties like battles or dealing with other supernatural beings. Another theme is loyalty, both within the pack and towards the alpha's mate. For example, in many fanfics, pack members will risk their lives for the alpha.
One common theme is the idea of fated mates. It's often that werewolves in these fanfics have a destined partner, and they can sense this connection on a deep, almost instinctual level.
One common theme is the struggle between human and beast. Since Ben 10 already deals with the idea of transforming into different alien forms, adding the werewolf element often explores the internal conflict of Ben or other characters when they are in a more animalistic state.
One common theme is identity. The werewolf characters often struggle with their dual identity in the world of Pokemon. Another theme is power. The werewolf abilities combined with Pokemon powers can create interesting power dynamics.
One common theme is the struggle between human and werewolf nature. Hermione often has to deal with the duality of the werewolf characters she interacts with. For example, in many fanfics, the werewolf may be kind-hearted but still has the wild instincts during the full moon.