He could try using his powerful magic to create a portal back to his own world. Maybe a spell like 'Portus' could work if he can focus enough.
First, he needs to understand the rules of the Groundhog Fanfic world. Once he figures that out, he might be able to find a key element or event that can trigger his return. For example, if there's a special groundhog - related prophecy or a magical object in the fanfic, he could use it to his advantage. Also, his own determination and the strength of his magic should play a role in getting him out.
Well, it could be really strange. Maybe he'd be super confused by the whole Groundhog Day - like repetition in the fanfic world. He might try to use his magic to break free from the odd cycle or situation he's in.
Well, it could be a side - effect of a powerful time - turning charm. In the wizarding world, time - related magic is extremely complex. If Harry was involved in an experiment or was caught in the crossfire of a time - magic battle, it might have led to him getting stuck in Groundhog Day. Also, it could be a plot by Voldemort or his followers. They might have found a way to trap Harry in this loop to stop him from fulfilling his destiny. They could have used some dark magic combined with a knowledge of Muggle concepts like Groundhog Day to create this strange situation.
Well, Hermione would be the first to take action. She'd be using her extensive knowledge of magic to try and find a solution. She might even come up with some complex spells or potions to try and break the loop. Ron would be a bit more laid - back, but still worried. He'd be there for Harry, listening to him talk about his experiences in the loop each time. Luna would have some really interesting and out - of - the - box ideas. She might suggest things like looking for invisible time - bending creatures or using her own unique brand of magic to disrupt the loop. His friends would all come together, each bringing their own strengths, to try and get Harry out of this strange situation.
Maybe he calls for help using a spell that alerts his friends, like Hermione or Ron. They then come to his rescue and figure out a way to open the cupboard from the outside.
You could also try to interact with the characters in a way that goes against the normal flow of the story. If everyone in the fanfic is always polite and formal, start being really out of character, like a modern - day person would act. This disruption might be enough to break the hold of the fanfic and let you get out.
Well, first, try to figure out the rules of the fanfic world you're stuck in. Maybe look for any plot devices or characters that could be your way out. If there are magical elements in the DxD world, seek out those who can manipulate magic to help you.
If she's stuck in a physical space like a small hole or a tight corner, she can try to wiggle her body slowly. Sometimes a little movement at a time can help her get free.
You could also try to find the 'author' within the fanfiction. If it's a self - aware fanfic, there might be a way to communicate with the person who's writing it. Appeal to them to let you out. Think of it like being in a dream and trying to wake yourself up by realizing it's a dream.
Well, if you're stuck in a 'Game of Thrones' fanfiction, one way could be to look for any plot holes or inconsistencies. Maybe use them as a way to break free from the narrative. For example, if there's a prophecy that doesn't quite make sense, question it until it disrupts the story's hold on you.
They could use their strong sisterly bond. Just like in their own world, they could rely on each other. Maybe they'd combine their powers in new ways to deal with the threats in the Harry Potter world. For example, using Piper's freezing power along with Phoebe's premonition to anticipate and stop attacks.