Well, there are several common themes. Firstly, the transformation through fire. Naruto might experience a change in his abilities or personality due to his interaction with fire - based elements. Secondly, fire as a source of inspiration for others in the story. His use of fire jutsu can inspire his comrades to be braver. Thirdly, the struggle to control the powerful fire within. This can lead to internal conflicts within Naruto as he tries to master his fire - based powers without causing harm to himself or those around him.
One common theme is power struggle. The main character with the fire zanpakuto often has to deal with others who either want to steal the power of the zanpakuto or are jealous of their new - found strength. Another theme is identity. As the character wields this unique weapon from a different anime concept, they often struggle with how it fits into their identity as a ninja in the Naruto world.
Growth is also a theme. Characters grow in their understanding of the will of fire. For example, they learn to be more selfless and dedicated to the greater good. It's about evolving as a ninja and as a person.
One common theme is perseverance. Naruto's will of fire is all about never giving up, and fanfictions often explore this through various challenges he faces. For example, he might be up against an enemy much stronger than him, but his will keeps him fighting.
In 'Naruto has a fire bloodline' fanfiction, a frequent theme is exploration of his heritage. Since the fire bloodline is not part of the original Naruto's abilities, it often leads to stories about his family history and where this bloodline came from. Additionally, there's the theme of rivalry. With new powers, Naruto might face new rivals, either from within the village or from other villages. This can create exciting new story arcs full of intense battles and character development. And of course, the theme of self - discovery is always present as Naruto figures out how to use his new powers effectively.
The idea of power and its limits is also common. In Naruto, there are different levels of power like different levels of chakra control. In Fire Emblem Fates, there are strong and weak units. Fanfictions might explore how a character's power from Naruto would be perceived in the Fire Emblem Fates world and how they would have to adapt to new power hierarchies.
One common theme is power combination. Writers often explore how Naruto's jutsu can be combined with the fire dragon slayer's abilities. Another theme is friendship, like Naruto making new friends from the fire dragon slayer world. Also, there's the theme of facing new and stronger enemies together.
One common theme is the passing down of values. The Will of Fire is often shown as something that is transferred from one generation to the next, like from the older ninjas to the younger ones. For example, in many fanfics, characters like Iruka Sensei play a role in teaching Naruto about the Will of Fire.
One common theme is the clash of cultures. Naruto's world has its own set of values, like the ninja code, and Fire Emblem: Radiant Dawn has its own complex political and social structures. Fanfictions often explore how these two different cultures interact. For example, how the idea of loyalty in Naruto compares to loyalty in the noble houses of Fire Emblem.
One common theme is friendship. Since it's about bonds, characters from Naruto and Fire Emblem often form strong friendships. Another theme is the struggle against a common enemy. They might combine their skills to fight a powerful foe. Cultural exchange can also be a theme, as the characters from different worlds learn about each other's cultures. For example, Naruto characters learning about the noble houses in Fire Emblem or Fire Emblem characters being introduced to ninja techniques.
One common theme is power struggle. Since wind and fire are powerful elements, characters often fight over who can control them better or use them more effectively. For example, in many fanfics, there are rival ninjas trying to outdo each other with their wind and fire jutsus.