Peter might be initially suspicious. After all, in his world, strange things often mean trouble. But then he could also be curious to find out more about this doppelganger. He might try to test the doppelganger's abilities, like seeing if they have the same spider - sense. If the doppelganger seems friendly, Peter could start to form a bond with them, sharing stories about their lives and learning from each other.
His friends would be very worried. For example, Ned would probably be constantly by his side, trying to find ways to help him remember. He might show Peter old photos or talk about their shared memories.
The media would probably go wild. There would be headlines everywhere. Some media outlets might portray him as a savior, while others might try to dig up dirt on him or question his motives for hiding his identity for so long.
Peter will probably be very confused at first. He's used to being part of the team, and suddenly being hunted by them is a huge shock. He might try to talk to them to clear up any misunderstandings.
In fanfiction, there are so many directions it could go. The doppelganger could be from an alternate universe. They might have a different personality, like being more aggressive or more cautious. Peter Parker would have to figure out if he can trust this other version of himself. There could be a struggle for identity too. Is the doppelganger trying to take over his life? Or are they there to help? It could lead to a complex and interesting story full of drama, action, and self - reflection.
The Avengers would initially be in shock when they find out Peter is sick. Clint Barton would be the one to keep a calm head and start organizing things. Wanda Maximoff would try to use her powers to ease Peter's pain if possible. Vision would use his vast knowledge to try and find a solution. They would all be very concerned and do everything they can to make Peter better, from getting the best medical help to providing a safe and comfortable environment for him to recover.
Some Avengers might be initially skeptical. Thor, for example, might not understand the power of a 'spider - boy' at first. But others like Captain America would probably see his potential and welcome him. Black Widow might be intrigued by his skills and try to train him further in espionage - related aspects.
The doppelganger could be a clone of Peter created by some mad scientist. The clone has Peter's memories up to a certain point but then has been programmed with different motives. So when they meet, Peter has to figure out how to deal with this exact copy of himself that has been turned into a tool by someone else.
Well, in this fanfiction, Peter Parker might meet the Avengers in a more casual setting. For example, he could be at a science expo where some of the Avengers are also present. Peter is there to show off his latest web - shooter design. The Avengers notice his intelligence and his unique abilities as Spider - Man. They then start a conversation with him, and from there, a relationship between Peter and the Avengers begins to form. This could lead to Peter getting involved in more Avengers - level missions and growing as a hero.
The meeting could be in a chaotic situation, like on a planet under attack. Peter is trying to save the locals and Kaine is just trying to survive. They end up having to work together. Peter shows Kaine how to use some of the alien tech to fight off the attackers, and Kaine teaches Peter some of his hand - to - hand combat moves that are useful in close - quarters fighting.
Perhaps Tony, knowing Peter's character, is somewhat expecting the interruption. He might have a wry smile on his face and then listen to what Peter has to say. He could also play it cool and make a joke about Peter's eagerness to interrupt his meeting, while still giving Peter a chance to explain his reasons.