They would probably be shocked. Demigods have extraordinary abilities, like being able to control water or run super fast. Percy's mortal friends, who are used to a normal world, would be taken aback by such powers.
Some of Percy's mortal friends might be excited. They could see the demigods as living legends. They would be eager to hear all about their adventures, the monsters they've fought, and the gods they've met. They might even want to be part of that world, at least for a little while. But others could be scared. The idea of beings with such power can be intimidating, and they might worry about getting hurt or being in over their heads.
In the fanfiction, Percy's mortal friends could find themselves in dangerous situations. Since demigods often attract trouble, the mortals might get caught up in battles against monsters. However, they could also learn a great deal from the demigods, like how to be brave in the face of fear and how to use their wits when in a tight spot. The demigods, in turn, might learn about the simplicity and normalcy of mortal life from Percy's friends.
They might be shocked. Percy is not an ordinary guy, and his abilities would be quite a surprise to them.
Some of Percy's school friends might be completely bewildered. They see these strange - looking kids (the demigods) showing up and whisking Percy away. They could be left standing there with their mouths open, not really understanding what just happened.
They might be cautious. After all, they don't know her and she's from Percy's world which could be full of unknowns for them.
Well, in some fanfictions, Annabeth's mortal friends might be initially in awe of Percy. They could be amazed by his powers like controlling water. Maybe they'll be a bit scared at first but then grow to like him as they see how he cares for Annabeth.
In fanfiction, when Percy's mortal friends meet Annabeth, there could be a lot of confusion at first. His mortal friends might be in awe of her as she has a strong and confident presence. They may be shocked by her knowledge of Greek mythology which seems so real to her.
Well, his friends' reactions would be quite diverse. Annabeth might see it as an interesting new development. She could be a bit protective, making sure that Percy, as a girl, isn't taken advantage of. Grover would likely be his goofy self, but also offer his support. He might make some silly jokes at first to lighten the mood. Other friends at Camp Half - Blood would also have different reactions. Some might be curious, some might be a bit hesitant, but overall, they'd probably accept Percy in this new form because they know it's still Percy deep down, with the same brave heart.
Grover would be really sad and sympathetic. He'd stay by Percy's side constantly, using his nature - related powers to help Percy get around. For example, he could use his ability to communicate with plants to create a sort of 'guide' for Percy in the forest or other natural areas. He'd also try to cheer Percy up with his music and his gentle nature.
His friends could also be divided. There might be those who immediately embrace Annabeth because they see her as an asset. For instance, if there are any students interested in architecture or strategy (which Annabeth is good at), they'd be thrilled. However, there could be some who are more territorial and feel like she's invading their space, which would create some interesting relationship dynamics in the fanfiction.
Some of the Avengers, like Thor, might have a more complex reaction. Since he is Loki's brother, he may feel a sense of responsibility towards the children. Others like Captain America would be cautious but fair, trying to assess if they are a threat. Iron Man, on the other hand, would probably be sarcastic and make some snarky remarks while sizing them up.