He would be intrigued and eager to read it.
Harry would likely be both excited and cautious. On one hand, his love for magic would make him eager to dive into the book. He'd be thinking about all the possible new magic knowledge he could gain. But on the other hand, he might be a bit cautious because he doesn't know if the fanfiction is reliable or if it might contain some dark or dangerous ideas. However, his curiosity would probably win out in the end, and he'd start reading it, perhaps with a bit of wariness at first.
Harry would probably be quite startled at first. The idea of Sirius and Remus in a relationship as depicted in the fanfiction photos is not something he's ever considered. But as he looks at the photos more, he could become more understanding. He's used to different magical concepts, and this could be just another one for him to wrap his head around. He might even feel a sense of pride that his father's friends were so interesting that fans created such elaborate stories and photos about them.
Snape would likely be shocked and then enraged. Harry is supposed to be the hero of the wizarding world, and seeing him drunk would be a huge disappointment. He would most likely drag Harry to his office, lecture him about propriety and the expectations placed on him as a wizard, and probably assign some form of punishment like a long detention. But as he observes Harry more closely during this time, he might start to wonder what drove Harry to this and if there are deeper issues that need to be addressed.
He might be amused. Fanfiction can be quite creative and sometimes funny, so he could just laugh it off and think it's an interesting take on the characters.
Often, Gwaine reacts with acceptance. He's not the type to shun Merlin just because of his magic. Instead, he'll likely embrace it as part of who Merlin is. He could say something like 'Merlin, your magic doesn't change a thing between us. You're still my friend.'
Tony could also be intrigued. Fanfiction often shows different perspectives on a person, and he might be interested in exploring what the writers have come up with. He might start discussing it with his friends or other people who are also fans of Skip, if there are any.
He'd probably be shocked. I mean, a tank is so out of place in the Naruto world. He might be scared too, not knowing what this huge, metal thing can do.
At first, Harry would probably be in shock. He's been through so much in his life, and this would be a huge new development. He might be a bit hesitant and scared, not sure if he's ready to be a father. But as time goes on, his Gryffindor courage would kick in and he'd start to take on the role with determination.
Well, it depends on the context. If he's in a place where he has some free time, like in his dormitory, he could immerse himself in the fanfiction. He could share it with his friends too, especially Hermione who would probably be interested in analyzing the old magic described in it. And who knows, it might even inspire him to try out some new magical ideas in a safe way, perhaps during one of their magic practice sessions.
If Zeus stumbles upon mal fanfiction, his reaction could be complex. He might initially be dismissive, thinking it's some strange human folly. But if it starts to gain popularity and he realizes it's making him look bad, he would be offended. Zeus is used to being in control and being seen as a powerful and just god. This mal fanfiction could make him look like a tyrant or a fool, which would go against his self - image. So, he may try to find a way to correct this perception, perhaps by sending some sort of sign or omen to the writers to stop or change their stories.
Harry might be shocked at first. He'd probably feel a sense of urgency to break the Imperius Curse. He could also feel a bit of pity for Draco, as Draco is being controlled against his will.