He could be furious. In many fanfictions, Snape is a strict character. Discovering something about a cupboard might lead him to suspect some sort of rule - breaking or hidden secrets. He might start an investigation right away to find out what's really going on.
In the fanfiction, Snape finding out about the cupboard could be a major plot twist. Maybe the cupboard was used to store a time - turning device or a portal to another dimension. Snape, being the intelligent and cautious wizard he is, would first try to assess the potential danger. He might gather more information by interrogating students or staff members who are suspected to be involved. His reaction would also be influenced by his loyalty to Hogwarts and his own personal motives at that time. If he thought it could harm the school or give an advantage to his enemies, he would do everything in his power to neutralize the situation.
In this fanfiction, Hermione might be shocked when she finds out about the cupboard. She could start an investigation to figure out what's been going on in there. Maybe it's a hidden place full of secrets related to Hogwarts' history.
Tony might be really surprised. He could have a range of reactions from being amused to being a bit uncomfortable, depending on what the fanfiction is about.
She might be initially shocked. If the fanfiction contains some untrue or inappropriate things about Clarke, Abby could be protective and try to find a way to stop it from spreading.
Tony could be really surprised. Maybe he'll first be curious to read it and see what others have imagined about Skip Westcott in this fanfiction.
Well, Dudley might be jealous at first. He's always been used to being the 'big shot' in his own little world. If he finds out Harry is famous in fanfiction, he could start to feel overshadowed all over again. Maybe he'll try to downplay it, saying it's just some silly made - up stories.
Charlie might be shocked and filled with anger. He could immediately seek to comfort Harry and ensure his safety. Maybe he'll vow to find the perpetrator within the context of the fanfiction's story.
She might be really surprised. Fanfiction can be quite different from the original story, and if Ada is used to the official Soukoku storyline, seeing all the creative and sometimes wild interpretations in fanfiction could be a shock.
In this kind of fanfiction, Cedric might feel shocked and angry. He could decide to protect Harry from further harm. Maybe he'll try to find the abuser and put a stop to it.
Abby might react quite strongly. Given her relationship with Clarke, she would likely be very interested in what is being written about her in the fanfiction. She may try to find the author to ask about their intentions. If the fanfiction has Clarke in some sort of dangerous or inappropriate situation, Abby would probably be quite worried and might even try to get it removed. However, if it's a positive and creative take on Clarke, she could see it as a compliment to her daughter - like figure and might encourage others to write more positive fanfiction about her.
Well, often in fanfiction, when Harry discovers his inheritance, it can completely change his social standing. He could be revealed as part of an ancient and noble magical family. This might lead to him getting more respect from the wizarding community and also open up new opportunities for him in terms of education and alliances. For example, he could be given access to rare magical libraries or training from the most skilled wizards in the family. He might also find out about family secrets that have been hidden for generations, which could help him in his fight against Voldemort or other threats.