Hermione is known for her academic approach to magic, so she might have a more refined and precise control over spells she has studied. Percy, on the other hand, could have a more instinctive magic related to leadership and order. Maybe he can magically organize things or people with ease.
Since they are twins in this fanfiction, they could have equal potential in different areas. Hermione's magical ability might shine in the classroom and in research, while Percy's could be more prominent in practical situations outside of school. But they could also learn from each other and develop new magical skills together. For instance, Percy could teach Hermione some of the practical magic he has learned from his experiences in the Ministry, and she could introduce him to new spells from her extensive reading.
Since Hermione is highly skilled in academic magic, she could use her knowledge to analyze Merlin's magic. Maybe she discovers ways to enhance his spells or make them more efficient. Merlin, with his natural and powerful magic, could help Hermione break free from some of the limitations of the Hogwarts magic system. For example, he might show her how to draw magic from sources other than a wand, which could be a game - changer for her.
They would likely raise them with a strong sense of honor and courage. Percy would teach them about the power of the sea and how to use it for good. Annabeth would instill in them a love for knowledge and strategy. They would also train their twins in combat skills to protect themselves in the dangerous world of demigods.
In the past, Tom's magical abilities were already quite strong even as a young student. His natural talent for magic was evident. However, if Harry travels back in time, he would bring with him the knowledge and skills he has learned in his own time. So in terms of spellcasting knowledge, Harry might have an edge as he knows spells that were not yet invented or commonly known in Tom's time. But Tom's raw power and his understanding of magic from his own era's perspective would be formidable.
They could develop a shared form of telepathy. Since they're twins, it's not far - fetched to think they could communicate without words. Maybe they could combine their magic to create a new kind of protective shield that's stronger than any single spell. Another ability could be the ability to sense each other's emotions more acutely, which could then be harnessed to boost their magic when they're in danger or facing a difficult task.
If Hermione was Remus's twin sister in fanfiction, their combined magical abilities could be really powerful. Hermione is already very intelligent and skilled in magic, and Remus is a powerful wizard too. Maybe they could combine their knowledge of spells and magic theory to create new spells or ways to combat dark magic.
Arthur's main ability is his leadership and his connection to the sword Excalibur which gives him great power in battle. He is also a skilled warrior trained in the ways of medieval combat. In contrast, Percy has his demigod powers. He can control water, which is a very powerful ability especially in combat situations near large bodies of water. He also has the enhanced strength and speed typical of a demigod.
Superman's strength, flight, and heat vision are very powerful. In comparison, characters like Captain America in the Marvel universe have more of a combat and leadership skill set rather than superhuman physical abilities. However, Thor also has super strength and the ability to control lightning, which could be on a similar level to Superman's powers in some ways.
Naruto has his chakra-based abilities like Rasengan and shadow clones. Frieza has his powerful energy blasts. Naruto's clones could be used to confuse Frieza while he tries to get in close for a Rasengan strike. Frieza's energy blasts are long - range and very destructive. However, Naruto's speed and agility in combat might give him an edge in dodging those blasts.
In a Warhammer Naruto crossover, Naruto's Rasengan would be a very unique ability compared to the magic and melee combat in Warhammer. His ability to quickly form and launch a powerful ball of chakra could be devastating against many Warhammer foes. On the other hand, the Warhammer wizards' large - scale spells would be on a different level than most Naruto jutsus in terms of area - of - effect. For example, a powerful fireball jutsu might be like a small - scale version of a Warhammer fire spell.
Well, Harry has the unique ability to see Thestrals because he has witnessed death. It's possible that one of their children could inherit this ability too, depending on how the fanfiction plays out. Hermione is very good at time - turning spells, though it's a dangerous magic. Their kids might inherit an inclination towards time - related magic, but hopefully in a more controlled and legal way. And of course, both Harry and Hermione are good at defensive magic, so their children would surely inherit strong defensive magical abilities.