Iron Man could be the main character. He could use his technological genius to enhance the wings. Maybe he creates a special alloy for the wings that can withstand extreme heat and cold, and also has built - in weapons. He would be constantly tinkering with the wings, trying to make them better, all while using them to fight off new threats.
Scarlet Witch could be the main character in an 'Avengers have wings' fanfiction. Her powers could interact in interesting ways with the wings. She could use her magic to change the appearance of the wings or even use them as a conduit for her powers. For example, she could send out energy blasts from the tips of the wings, or use the wings to fly faster by enhancing them with her magic.
I think Spider - Man would make an interesting main character. He's young and has a different perspective compared to the more experienced Avengers. His journey of growing up and becoming a more integral part of the team could be a central theme in the fanfiction. He also has his own set of personal problems like school and his relationships which could add depth to the story.
Captain America might be the main character. He represents the heart and soul of the Avengers in many ways. In this fanfiction, he could be the one leading the team through an emotional crisis, using his unwavering moral compass to guide them and protect the heart of the team and the world they are trying to save.
A new superhero created specifically for the fanfiction could be the main character. This character could have a power that is a combination of different Avenger's powers, like being able to have super strength like Hulk and also fly like Iron Man. Their unique abilities would draw the attention of the Avengers, making them the center of a harem - like story.
Hermione could be a great main character. She's smart and curious, so if she ended up in the Wings of Fire world, she would be eager to learn about the dragons and their society. She could use her knowledge of magic from Harry Potter to interact with the new world and might even try to find a way to combine the two magics.
Obviously, the cook would be one of the main characters. They could be a young and ambitious chef who has always dreamed of working in a place as exciting as the Avengers Tower.
There could be a magical creature that takes on a human - like form and has black angel wings. This creature could be a guardian of some sort, maybe of an important magical artifact. It might initially be seen as a threat but is actually there to protect the wizarding world. When Harry discovers this creature, they form an unlikely bond, and the black angel wings become a symbol of their unique relationship.
Maybe it's an orphan girl, like Emma, who has always felt different and then finds out she has wings which are the key to her true identity. She might be from a lost race of winged people. The story could be about her journey to find her people and her place in the world.
It could be Naruto. Since he is the main character in the original series, it would be natural for him to be the focus in this fanfiction as well. The butterfly could have a special connection to him, like guiding him on a new adventure or helping him unlock a new level of his power.
Maybe it's a hybrid creature that has been created accidentally through some magical experiment gone wrong. It has wings, horns and hoofs and is trying to find its place in the world. It could be a really interesting main character as it would have to deal with not only the normal MLP problems but also the fact that it's different from everyone else. It could start out as an outcast but gradually earn the respect and friendship of the other characters. For example, it could use its unique abilities to save a group of ponies from a dangerous situation, which would make them see it in a new light.
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.