Iron Man could also be in the lead. He's highly intelligent and resourceful. He would be able to quickly analyze the situation in the past and come up with plans to deal with any problems. His ability to improvise and his technological know - how would be very useful. He might be able to use the limited resources in the past to create something useful for their mission.
Captain America is a likely candidate. He has a strong sense of leadership and his own past experience from the World War II era. So he would be able to navigate the past more easily and make decisions based on his knowledge of that time. Also, his moral compass would guide the team in a new and different environment.
Thor might take the lead as well. He has a long - standing history and is used to different realms and time periods. His god - like powers would give him an edge in dealing with any threats in the past. And his sense of honor and duty would make him committed to leading the team in the right direction while in the past.
I think Iron Man would be a likely candidate to take the lead. He has the resources and the technology. He could build advanced medical equipment or suits to aid in Spiderman's recovery. His genius - level intellect would also allow him to quickly analyze what's wrong with Spiderman and come up with solutions.
Ant - Man would be a likely candidate as his power already involves size - changing. In fanfiction, his ability could be enhanced or malfunction, leading to all kinds of interesting scenarios. For example, he could accidentally make all the other Avengers the same size as him, creating a whole new dynamic for the team.
Iron Man would be a likely candidate. He's already shown a sort of father - figure - like relationship with Peter in the movies. He can offer Peter high - tech resources, valuable advice on being a superhero, and also teach him about responsibility in a more modern way.
Makoto Naegi is likely to take the lead. He has shown great leadership skills in the original Danganronpa. His ability to see the good in people and his determination to survive and bring others along would make him step forward in this new situation.
Captain America could be a likely character to be betrayed. He represents the old - school values of the Avengers, and in a more modern, cynical world within fanfiction, some might see his ideals as outdated and turn against him. Also, Tony Stark. His wealth and sometimes over - confident attitude could make some of the other Avengers, especially those with more humble backgrounds, feel resentful and potentially betray him. And Thor, being an Asgardian, might be betrayed due to the other Avengers' mistrust of his alien nature or the potential threat Asgard could pose.
Hawkeye might be one. He's always on high alert and if he senses any threat from Team Red, he could be the first to draw his bow. He's very protective of his team and the world, so any sign of trouble from a new group could set him off.
Thor would be a likely candidate. Since he is Loki's brother, he already has a connection with him. Thor might be the one to convince the other Avengers to give Loki a chance and be the first to reach out and try to befriend him in this new situation.
Captain America would be a likely candidate. He's all about justice and if he thought Spider - Man was doing something wrong, he'd go after him. Also, Iron Man. He's often quick to act and if he saw Spider - Man as a threat to his technology or the safety of the world, he'd be on the chase. Black Widow too, as she's used to tracking down targets and if she was given the order to bring in Spider - Man, she'd do it.
Magnus Bane and Doctor Strange would make a great pairing. They are both powerful magic - users. Magnus could introduce Doctor Strange to the magic of the Shadow World, and Doctor Strange could share his knowledge of the mystic arts from the Marvel Universe. They could collaborate on spells and magical defenses against common enemies.
Tony Stark is a likely focus. His intelligence and experience with technology, especially time - travel technology in the movies, make him a central figure. He could be the one to figure out the mechanics of time travel and lead the Avengers in their time - traveling adventures.