There probably is. Fanfiction writers often come up with really creative crossovers. However, the quality can vary a great deal. Some might be really well - written with interesting plotlines that blend the Naruto and Soul Eater universes in a unique way, while others might not be as good. It's all about exploring different interpretations of the characters and their worlds.
I'm afraid I can't recommend a particular 'Naruto is Asura Soul Eater' fanfiction. However, when you search on those fanfiction platforms, look for ones with high ratings and positive comments. Also, pay attention to the writing style. If the summary grabs your attention and the writing seems polished, it's more likely to be a good read.
Black Star would probably see Asura as a new opponent to prove his strength against. He would be eager to fight, shouting his usual boasts about being the one to defeat the most powerful foe. However, he might quickly realize that Asura is on a whole different level and would need to rely on his friends more than he thought.
Perhaps in this crossover, Asura's power is somehow transferred to one of the weapons in the Soul Eater world. This weapon then becomes an uncontrollable force, and the meister has to find a way to either contain or purge the Asura - like power within it. It could also cause a rift between the meister and their friends as they struggle to deal with this new, dangerous situation.
There are many places to find such fanfiction. Firstly, Fanfiction.net has a large collection. Browse through the Naruto and Soul Eater sections and look for stories that specifically mention Patty. Another option is Archive of Our Own. It has a great tagging system which can help you narrow down the search to exactly what you're looking for. Some fanfiction might be about how Patty from Soul Eater could interact with the characters in Naruto, or it could be a more complex crossover story with an interesting plot.
Perhaps in this crossover, the concept of the tailed beasts in Naruto are related to the Kishin in Soul Eater. The tailed beasts are seen as powerful and dangerous entities, much like the Kishin. A group of characters from both universes, including Naruto, Maka, and Soul, come together to find a way to either control or destroy these powerful forces that threaten both their worlds. They would have to learn from each other's strengths and weaknesses to succeed.
First, you need to establish the connection between the two universes. Decide how the Naruto and Soul Eater worlds will interact or collide. For example, you could create a portal that transports characters from one world to the other. Then, focus on the neglected aspect. If it's a Naruto character in Soul Eater, show how their ninja abilities are not understood or valued at first. Maybe they are seen as odd or dangerous. Outline your story, including a clear beginning, middle, and end. Have a conflict that the neglected character has to overcome, like gaining the trust of the Soul Eater characters or learning to use their powers in a new way.
I really liked 'Ninja Souls in Death City'. In this fanfic, Naruto characters are transported to the world of Soul Eater. It's cool to see how Naruto's determination and the power of chakra blend with the Soul Eater concept of souls and death. The author does a great job of making the crossovers believable and the action scenes are intense.
First, you need to understand the core elements of each series. For Naruto, it's the ninja world, chakra, and the various clans. In Soul Eater, it's about meisters, weapons, and the concept of souls. And for Excalibur, it's the powerful and somewhat eccentric sword. Then, come up with a unique concept for the crossover. Maybe a powerful weapon in the Naruto world is actually related to Excalibur, and a Soul Eater character gets involved. Start with a strong opening that grabs the reader's attention, like a sudden appearance of a strange character from one of the other universes.
The concept of transformation is a common theme. Naruto has his own forms like Sage Mode and Nine - Tails Chakra Mode. In Soul Eater, there are also different forms and levels of power. Fanfictions often explore how Naruto's transformation abilities could be related to or affected by the Soul Eater world's power - up systems. Additionally, the theme of good vs. evil is prominent. With Naruto's strong sense of justice and the Soul Eater world's battles against evil, these fanfictions usually have some sort of conflict between good and bad forces.