Perhaps she could have a special connection to the magic of Hogwarts itself, just like Dumbledore did. So she could be able to control certain aspects of the castle that others can't, like opening secret passages more easily or sensing when something is wrong within the school's wards.
Since Dumbledore was a very powerful wizard, Hermione could potentially have a greater aptitude for advanced and ancient magics. For instance, she might be able to perform spells that are long forgotten by most wizards. And her magic could be more refined and powerful in general, allowing her to handle difficult situations with more ease compared to her original self in the normal story.
If Hermione was Dumbledore's granddaughter in fanfiction, it would likely make her an even more important figure at Hogwarts. The teachers might treat her differently, perhaps with more respect or higher expectations. And she could have a different role in the Order of the Phoenix too, being related to Dumbledore. She might be given more dangerous or important tasks.
Naruto might gain the ability to tap into a primal energy within him due to his wrath powers. This energy could allow him to heal faster when injured in battle. Also, he could have the power to influence the emotions of his enemies. When they look into his eyes during his wrath - filled moments, they could be filled with fear or hesitation. Additionally, his physical attacks could carry a sort of 'wrath - curse' that weakens his opponents over time as they are continuously exposed to his wrath - powered strikes.
Maybe there could be a secret about a powerful magic that has been passed down in the McGonagall family. Hermione might discover that she has an innate ability for a type of magic that no one else in Hogwarts knows about. Or perhaps there's a family secret regarding the history of Hogwarts itself, like a hidden room or passage that only the McGonagalls are supposed to know about.
She would likely have a combination of her natural magical abilities from the wizarding world and the technological know - how from her father. So she could use spells to enhance her technological gadgets or use technology to boost her magic. For example, she might be able to create a wand that also functions as a high - tech weapon, or use a spell to hack into a computer system.
She could have the power to control water, of course. This means she could make water move in any way she likes, like creating waves or even making water spouts. She might also be able to breathe underwater without the need for spells like the Bubble - Head Charm. Another power could be the ability to communicate with sea creatures, which would be really cool. She could ask for help from whales or dolphins, for instance.
He could have enhanced physical abilities like Black Widow. So, he'd be super agile, able to jump from high places and land safely, and have great reflexes. Also, he might be a master of disguise, which would be really useful in the wizarding world. He could blend in with different magical creatures or people to gather information.
One possible plot could be that Hermione starts having strange dreams or visions that lead her to discover a hidden family connection to Merlin. She then embarks on a journey to learn more about her heritage, which takes her to ancient magical places and uncovers long - lost spells or powers related to Merlin.
Often, she is a character full of contradictions. On one hand, she has the potential for great power due to her family lineage. On the other hand, she is determined to be different from Grindelwald. In fanfiction, this can lead to interesting storylines where she has to face challenges from both those who fear her because of her family name and those who want to use her for their own dark purposes.
He could have the ability to manipulate the concept of law itself. For instance, he could make it a 'law' that any attack aimed at him misses. This would be like a natural defense mechanism. Another ability could be to set laws on the use of chakra, like 'only I can use fire - style jutsu in this area' which would disrupt his opponents' combat strategies.
Dumbledore might be motivated by his over - arching plan to defeat Voldemort. He could see Hermione as a sacrifice that needs to be made. Maybe he believes that by betraying her, he can gain some crucial information from the enemy that will ultimately lead to Voldemort's downfall.