The Hulk could be a key character in this fanfiction. His raw power might be both a concern and an asset when dealing with the lost creatures. Black Widow and Hawkeye could also play important roles. They are more in tune with the earthly aspects and could be the ones to first make contact with the lost creatures on a more personal level. Among the lost creatures, there might be a young and curious one that forms a special bond with one of the Avengers, like Spider - Man if he were part of the team. This young creature could act as a bridge between the two groups.
Obviously, the Avengers themselves would be main characters. That includes Iron Man, with his brilliant mind and high - tech suit. Captain America, the symbol of justice and leadership. Thor, the god of thunder, who could have an interesting interaction with the lost creatures perhaps due to his own otherworldly nature. And then there are the lost creatures. There could be a leader among them, a wise and powerful being that serves as a counterpart to the Avengers' leaders.
One possible plot could be that the lost creatures are actually ancient beings with special powers. The Avengers discover them and at first think they are a threat. But then they realize these creatures were once protectors of the earth. They team up to fight a common enemy, like an alien force that wants to use the lost creatures' powers for evil.
Definitely Iron Man's protege. He could be a young genius who inherits some of Iron Man's technology and tries to lead the little Avengers. Then there's Spider - Man. His youth and agility make him a natural fit for the team. And of course, Ant - Man's daughter. She already has experience with shrinking technology and could bring a unique perspective to the group.
There could be a character like Nova, a young hero with cosmic powers. He could bring a fresh perspective to the team. Another could be Kate Bishop, Hawkeye's protege. She has great archery skills and a sharp mind. And of course, Miles Morales could be part of it too, with his unique spider - powers.
The main characters would obviously be the five Avengers. It could be Iron Man, Captain America, Thor, Black Widow, and Hulk. And of course, the baby would be a central character as well. Maybe the story could focus on how each of the Avengers interacts with the baby differently. For example, Iron Man might use his technology to create baby - friendly gadgets, while Thor might tell the baby stories of Asgard.
Obviously, the Avengers themselves would be main characters. Iron Man could be the one who funds the high - tech medical equipment in the hospital. Thor might have a hard time adjusting to the human medical procedures. And Black Widow could be using her espionage skills to find out if there are any threats in the hospital.
Maybe some new characters who were inspired by the Avengers but have their own unique powers. They could be from different parts of the world or even from other planets. One might be a girl with the power to control nature and she joins the new generation of heroes in 'The Avengers Heroes of Tomorrow Fanfiction'. Another could be a young man who has super speed and was inspired by Quicksilver. There could also be a character who has psychic abilities and he was drawn to the Avengers' cause of protecting the world.
Definitely Percy Jackson from 'The Lightning Thief' and Iron Man from the Avengers would be main characters. Iron Man with his high - tech gadgets and Percy with his demigod powers would make for an interesting duo. They could play off each other's strengths and weaknesses. Maybe Iron Man is constantly trying to analyze Percy's powers with his technology while Percy is just like 'Let's just go and fight already!'
I think some new characters related to the future kids could also be main characters. For example, a mentor figure for the Avengers' kids, someone who was a sidekick to the original Avengers and now has to guide the next generation. Or perhaps a non - superpowered friend of the kids who provides a different perspective and helps them in more practical ways, like coming up with strategies or providing moral support.
The main characters would surely include Loki, who might be the catalyst for the story. Then there's Thor, his brother, who would try to bring Loki into the Christmas spirit. Hulk could also be a main character in a funny way. Imagine Hulk trying to put up Christmas lights and accidentally destroying half of the building. And of course, the core Avengers like Hawkeye, who could be teaching Loki how to shoot arrows at Christmas - themed targets, and Vision, who might explain the deeper meaning of Christmas to Loki using his knowledge of the Mind Stone.
One possible main character could be the son or daughter of Iron Man. They might inherit his genius and some of his tech - savvy ways. They could also have a bit of his cocky attitude at the start but grow into a true hero throughout the story.