One interesting plot twist could be that Hermione's snake form is actually a key to unlocking an ancient prophecy. In the fanfiction, no one realizes this until she accidentally discovers it while in her snake form exploring an old chamber. This could change the whole course of the story as everyone now has to protect Hermione and figure out how to fulfill the prophecy.
A really unexpected plot twist could be that Hermione's snake form is not just a regular animagus form. It could be part of a reincarnation cycle in the wizarding world. In the fanfiction, she discovers that she was once a powerful snake - like wizard in the past and her current form is a way for her to regain her past powers. This completely changes her understanding of herself and her role in the wizarding world.
Another common plot twist is Hermione having a hidden connection to one of the other schools participating in the tournament. Maybe she discovers that she has family ties to a student from Beauxbatons or Durmstrang. This connection then leads to her getting involved in political or magical intrigue between the schools that wasn't present in the original story. It can involve her using her intelligence to navigate through these complex relationships and keep Hogwarts safe.
Well, a really interesting plot twist could be Hermione's role in the Slytherin house. She could become a leader, using her intelligence to reform the house's more negative aspects. Or, she might be caught in the middle of a power struggle between different Slytherin factions. Also, her interactions with the Slytherin pure - blood families could be full of drama. Maybe she discovers a family secret that could change the whole wizarding world.
One cool plot twist is when Hermione discovers that Edward has a hidden power that is related to her magic. Maybe he can absorb and use some of her magic energy, which leads to a whole new set of challenges and adventures as they try to understand and control this new aspect of their connection.
In some fanfictions, the plot twist is that Hermione's magic has a different effect in Middle - earth than it does in the Harry Potter world. For instance, her spells might accidentally cause a rift between different races in Middle - earth, and she has to find a way to fix it while also dealing with the main quest of the dwarves to reclaim Erebor. It adds a whole new layer of complexity to the story.
A really interesting plot twist could be that Snape was under a spell all along that made him seem so cold and distant, and Hermione discovers it. This changes the whole dynamic between them. Another twist could be that Hermione is actually related to someone from Snape's past in a way that they never expected, which brings them closer.
In some fanfictions, Hermione as an animagus snake can be portrayed as having enhanced stealth. She might use her snake form to access restricted areas in Hogwarts, slithering through small cracks and hidden passages. For example, she could be on a mission to discover a hidden secret related to the founders of the school, and her snake form gives her an advantage in exploring the castle's nooks and crannies.
A great plot twist could be that the Death Eater she's betrothed to is actually a double agent himself. All along, Hermione thought she was the one with the upper hand in the undercover operation, but it turns out he's been playing a long - game too. This would completely change the power dynamic between them and add a whole new layer of complexity to their relationship.
One interesting plot twist could be that despite their initial animosity, Hermione and Draco find they have very similar parenting styles when it comes to discipline. They both believe in strict but fair rules, which surprises everyone around them. Another could be that in the parenting class, they are paired for a project that forces them to spend a lot of time together outside of class, and during this time, they discover a mutual respect for each other's intelligence.
One common plotline is that Hermione discovers her ability to be a lion animagus while researching in the library. It could be that she stumbles upon an ancient spell or a long - forgotten text that triggers her transformation. Then, she has to keep it a secret from most of the Hogwarts faculty while learning to control her new form.
One interesting plot could be that the leopard animagus is a secret protector of Hogwarts. They prowl around the grounds at night, keeping an eye out for any dark wizards or dangerous creatures. When the main characters start to suspect something strange is going on, they begin to investigate and eventually discover the truth about the leopard animagus.