The main character could be Hermione Granger. Since she is very intelligent and has a strong sense of justice, she could easily be re - imagined as a lawyer. She could use her vast knowledge of magic and her quick thinking to bridge the gap between the two worlds and help the Avengers out. For example, if there was a spell that was being misused in the Avengers' world, she could figure out how to stop it legally.
Well, perhaps the lawyer character could be a Muggle - born in the Harry Potter world who is a huge Avengers fan. They somehow end up in a situation where they have to use their lawyering skills to represent the Avengers against some sort of magical - technological threat that combines elements from both universes. They might argue about who has the right to certain magical artifacts that are now in the hands of tech - savvy villains.
There could be an entirely new goblin character created just for this fanfiction. This goblin lawyer could be an outcast from the goblin community because of his more progressive views on wizard - goblin relations. Harry, seeing his potential, hires him to help with his legal battles that require a fresh perspective.
Well, first of all, the Avengers would need to locate Harry Potter. Maybe Hawkeye could use his eagle - eyed skills to spot him. Then, Captain America could lead the team in a rescue mission. Hulk could be the muscle, smashing through any obstacles in their way. Black Widow could use her combat skills to take out any enemies nearby. And finally, they could use the Quinjet to escape with Harry to safety.
It could be Hermione. She's always been very book - smart and she could have decided to study law in the wizarding world. She already has a great understanding of the rules and regulations at Hogwarts, so it would be a natural progression for her to become a lawyer. And she would be very dedicated to helping Harry with any legal issues.
Luna Lovegood might be an unexpected but interesting choice. She has a unique perspective on the wizarding world. While she may seem a bit eccentric, her ability to think outside the box could be useful in a courtroom. She could come up with creative defenses for Harry, and her calm and dreamy nature might be able to sway a jury or judge in Harry's favor.
Another theme is justice. Harry, being the hero we know from the original series, is always striving for justice in these fanfictions. He uses his legal skills to right wrongs and protect the innocent in the wizarding world. For example, in many of these stories, he defends those who are wrongly accused of using dark magic.
One possible plotline could be Harry using his knowledge of the wizarding laws, which he learned through his years at Hogwarts and his experiences with the Ministry of Magic, to defend wrongly accused wizards in a wizarding court. Another could be him trying to reform the wizarding legal system which he might find full of loopholes and biases.
Hermione Granger could be a common character. Given her intelligence and knowledge of the wizarding world laws (she's always reading), she could easily be imagined as a brilliant lawyer. She would use her quick thinking and vast magical knowledge to build strong cases.
In fanfiction, Raven could be an interesting addition to the Harry Potter and Avengers universes. Maybe she has some sort of magic ability that links her to the wizarding world of Harry Potter and at the same time, she might possess powers that could make her fit into the Avengers' world. For example, she could be a powerful witch who also has enhanced physical abilities like the superheroes in the Avengers. She might interact with Harry Potter characters by using her unique powers to solve some magical problems at Hogwarts. And in the Avengers' side, she could be a new recruit with her own set of skills and backstory.