It could be that Harry discovers he has some sort of connection to the Infinity Stones. So, the Avengers seek his help to understand and control the power of the Stones. Along the way, he has to deal with his own past traumas as well as the new threats in the Marvel world. He might teach the Avengers some magic too, like how to apparate short distances for quick escapes or attacks.
The plot could involve Harry Potter being transported to the Avengers' universe. He might use his magic to help the Avengers fight against a common enemy, like Thanos. For example, his invisibility cloak could be used for stealth missions, and his spells could be a new form of defense against alien threats.
Well, perhaps Harry discovers the Avengers through some magical means like a spell gone wrong that transports him to the MCU world. He could be in awe of their powers and decide to learn from them, and then try to incorporate their fighting styles into his own magical battles.
In this fanfiction, Harry's Animagus skills as an Avenger might also lead to some interesting character interactions. He could teach the other Avengers about magic and how his Animagus form works. For instance, Tony Stark might be intrigued by the magic behind it and try to find a scientific explanation or a way to replicate it. Meanwhile, Steve Rogers could be more interested in how Harry uses this ability in combat situations.
Maybe Harry could use some of his magic skills to assist the Avengers in a battle against a powerful enemy. For example, he could use a spell to freeze the bad guys momentarily while the Avengers strike.
In this fanfiction, perhaps the reason for their marriage was a prophecy that only their combined powers could defeat a coming evil. Harry Potter, with his knowledge of the wizarding world and his own powerful magic, and the Avenger, with their superhuman abilities and high - tech gadgets, start off not getting along well. But as they face challenges together, they grow closer. They might have to deal with jealousy from both the wizarding and superhero communities, but in the end, they prove that their union is a force to be reckoned with.
Perhaps Harry discovers a way to travel to the Marvel universe and becomes enamored with the Avengers. He might then try to prove himself to them, showing off his magic skills and offering to help them in their battles.
In many fanfictions, Harry might have gained unique powers or skills that caught the Avengers' attention, leading to his inclusion.
Yes, there are quite a few out there. Some focus on Harry's unique abilities being transferred into the Death Avenger universe, creating really interesting crossovers. For example, there are fanfics where Harry uses his magic in unexpected ways within the Death Avenger setting.
If Harry Potter became an Avenger, it could lead to interesting crossovers and storylines. His experiences in the wizarding world could give him a different perspective in battles against villains.
There are likely many such fanfictions out there. You could also check some Harry Potter or Avengers fanfiction communities on social media platforms like Reddit. Fans often share their favorite works or even write their own. They might be able to point you towards a 'Harry is an Avenger' fanfiction.