Perhaps in the fanfiction, the Avengers meet future Morgan Stark who has been trying to carry on her father's legacy. She might be leading a new group of heroes, and the Avengers could team up with them to face a common enemy. For example, she could have developed advanced Iron Man - like suits for her team. The story could also explore how the Avengers react to seeing the grown - up daughter of Tony Stark and how she has been influenced by her father's sacrifice.
The Avengers might initially be shocked to see Morgan Stark all grown up. Then, they could start interacting with her in a very friendly way, like she's family. Thor might be very protective of her, remembering Tony. Captain America could be impressed by her leadership skills.
Since he might be related to Tony Stark, there could be an emotional connection for the other Avengers. They might feel a sense of obligation to protect him or guide him, which changes their group dynamic. For example, Captain America might take on a more father - figure role towards Peter. Also, his presence could create some jealousy or competition among the Avengers who want to be his mentor or closest ally.
There could also be a scenario where the Avengers travel back in time to seek Howard Stark's help. Maybe they need his unique insights on some ancient technology or a threat that has roots in his era. So they go back in time and encounter him.
One possibility is that the Avengers are facing a threat related to some old Hydra experiments that Howard Stark was once involved in. They meet him to gather information about the experiments, like the location of hidden files or the identities of key Hydra operatives from that time. Howard Stark, being the brilliant mind he is, joins forces with the Avengers to stop Hydra's resurgence.
Future Loki might interact with the Avengers in a cautious way. He knows their past opinions of him and tries to prove himself. He could start by sharing small bits of useful information. For example, he might tell Iron Man about a weakness in a new enemy's technology.
They would be all over him! Steve would probably have a big, warm smile on his face and just be in awe of how small and precious he is. Clint would make silly faces to make the baby laugh. Bruce might be a bit more cautious at first, but then he'd be charmed by Peter's little giggles.
It could be Iron Man, Tony Stark's father is Howard Stark. So Tony would have a very emotional and complex relationship in this meeting. He might be the main character as he gets to know his father in a different way and learn more about his past.
In such a fanfiction, perhaps the Avengers could be shocked by how much Peter has grown and developed in the future. He might show off new powers or skills he's acquired. For example, his Spider - Sense could be even more advanced, allowing him to predict complex threats far in advance. And he could offer new perspectives on old foes the Avengers have faced, based on his future experiences.