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.
Doctor Strange could be the one to take the lead. Given his vast knowledge of magic and the mystic arts, if Spiderman's injury or ailment has a magical component, Strange would be the most qualified. He could also use his magic to shield Spiderman from further harm while the recovery process is underway.
Captain America might take the lead. He is a natural leader and has a strong moral compass. He would be able to offer Spiderman emotional support and also organize the other Avengers in their efforts to help. He would ensure that everyone is working towards the common goal of getting Spiderman back on his feet.
Thor would be the most likely. Since Thor has a connection to Norse mythology already, he would be familiar with Sleipnir. He might see Sleipnir as a symbol of his home realm and would quickly bond with it. They could communicate in a way that the other Avengers can't, sharing stories of Asgard and the great battles there.
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.
Iron Man could also be a likely candidate. Tony Stark is known for his charm and his ability to work with all kinds of people. He might be intrigued by Flash Thompson's bravado and see it as a starting point to shape him into a better person. He could offer Flash some cool tech gadgets and in the process, form a friendship. Stark would likely use his wit and intelligence to get through to Flash and show him a different way of looking at things.
Captain America is a likely candidate. He has a strong moral compass and a sense of protectiveness. He would see it as his duty to take care of the baby. His old - fashioned values would make him a great caregiver, like making sure the baby has a proper upbringing even in the middle of all the chaos in the Avenger's world.
Black Widow could be the most interesting. She has a mysterious past and a lot of skills in espionage and combat. Her teaching would be full of practical knowledge. She could teach students how to read people, how to be stealthy, and how to fight if necessary. Her no - nonsense attitude would make her a strict but effective teacher, and students would learn a lot about survival and self - preservation from her.
Thor would be a strong contender. His god - like strength and the power of Mjolnir, or Stormbreaker, could be very effective against the Titans. He could fly in and smash the Titans with his hammer, and his lightning powers could also do significant damage.
Captain America. He values honor, courage, and justice, which are all qualities that Robin also embodies. Cap would respect Robin's skills in combat and detective work. They could lead a team together, with Cap providing the strategic leadership on a large - scale battlefront, while Robin uses his stealth and intelligence to gather intelligence and take on enemies from the shadows.
The Green Goblin could be a likely villain. He has a long history with Spiderman and his maniacal nature would put him at odds with both Spiderman and Deadpool. His glider and pumpkin bombs would be a real threat to them.
Venom could be another one. He has a vendetta against Spiderman, and knowing he's injured, he would likely try to finish him off once and for all. He could lurk in the shadows waiting for the right moment to attack.
I think Captain America would be really popular. He has that classic good - looks and a strong sense of right and wrong. He'd be the kind of guy who stands up to bullies and is always there to help others. In high school, those are qualities that would make him well - liked. Also, his leadership skills would probably make him a natural fit for student council or leading group projects.