One storyline could be that the British mage is accidentally transported to the Naruto world. They then have to find a way to get back home while also dealing with the various threats in the Naruto universe. Along the way, they could make friends with Naruto and his friends and use their magic to help in battles against the Akatsuki.
A British mage might struggle to fit in at first. In the Naruto world, power is mainly based on chakra. But the mage could start by using their magic secretly. For example, they could use magic to heal wounds in a way that's different from medical ninjutsu. Eventually, they might teach some of their magic to Naruto characters or learn from them about chakra. It could be a two - way exchange of knowledge and skills that would change the Naruto universe in unique ways.
His chakra. Chakra is like the energy source in Naruto's world. In the fanfiction, this chakra could be translated into a very powerful form of magic in Fairy Tail. It gives him the ability to perform various powerful techniques, much like mages in Fairy Tail use their magic.
In that fanfiction, it might be designed that way. Naruto has incredible powers in his own series, like his various jutsu. If translated into the Fairy Tail world in fanfiction, his skills could potentially make him very powerful. But it also depends on how the author of the fanfiction interprets and balances the power systems of both universes.
In this fanfiction, Kakashi could also be Naruto's mentor in magecraft. Kakashi is known for his adaptability. He could start to study mage powers along with Naruto. They could learn together about new forms of magic, and Kakashi could use his combat experience to help Naruto understand how to use his mage powers in battle situations.
The unique feature is the blend of magic and ninjutsu. For example, in some fanfictions, characters can cast spells like mages while still using their ninja tools. It's like a new power - up for the Naruto characters.
Sakura could be a great ally. She's already a skilled ninja with medical abilities. In a mage - influenced story, she could learn some magical healing spells to complement her existing skills. Her intelligence would also help Naruto in strategizing when they face magical threats.
One idea could be a crossover where a Naruto character, like Naruto himself, somehow ends up in the Fairy Tail world and meets a cute mage, perhaps Lucy. They could team up on a mission and Naruto's unique ninja skills combined with the magic of the Fairy Tail mage would make for an interesting story.
Naruto himself is often a popular character in these fanfictions. Writers like to explore how his existing powers could interact with blood mage abilities. Sasuke is also a common choice. His Sharingan and his quest for power could be combined with blood magic in interesting ways.
Power and its consequences. Since black mages often have great and sometimes dangerous powers, many fanfictions explore how this power affects the character and the Naruto world around them.