Spiderman's age in the Infinity War comic varies depending on the specific storyline and continuity. But generally, he's depicted as a young adult, likely in his late teens or early twenties.
He might also have an emotional reaction. Spiderman is a very empathetic character. If the fanfiction shows some really tragic events during the Infinity War, he could be deeply affected. This could lead to him being more determined to prevent such tragedies from happening in his reality.
It could make him more cautious. After seeing all the chaos in the Infinity War fanfiction, he might be more careful in his actions. He wouldn't want to rush into situations without thinking, like some characters might have done in the fanfiction.
In this type of fanfic, the Infinity Stones could have a very different effect in the Harry Potter universe. For example, the Time Stone could be used to reverse dark spells or resurrect fallen wizards. However, the Stones' power might also be limited by the magic rules of the wizarding world. The fanfic could delve into how the characters from both universes adapt to the presence of the Stones and how they use or misuse their power.