Yes, there are some out there. You can start by looking on popular fanfic websites like Fanfiction.net or Archive of Our Own. However, the quality can vary greatly. Some might focus on their different powers and how they could interact in a shared universe, while others might explore a more romantic relationship between Blackfire and Naruto.
One possible plot could be that Blackfire somehow ends up in the Naruto universe. Naruto, being the curious and friendly ninja he is, tries to help her understand this new world. They then team up to face a common enemy, perhaps an enemy that is a threat to both the Teen Titans' world and the Naruto world. Their different powers, Naruto's jutsus and Blackfire's alien abilities, would be combined to defeat the foe.
Naruto could fit in by sharing his knowledge of the ninja world. This could include things like how to make different types of ninja tools or how to perform certain stealth techniques. In return, the Teen Titans could teach him about teamwork in a different way than he's used to in Konoha. His unique abilities like summoning animals could also be a huge asset when they are up against tough enemies.
The relationship could also develop because of a misunderstanding. Maybe Blackfire is trying to help the Teen Titans in her own way, but Robin misinterprets her actions as being sneaky. This causes a rift between them at first. But as they work through the misunderstanding, they learn more about each other. Blackfire explains her motives, and Robin realizes he was wrong. This new understanding could lead to a closer bond, with Robin seeing Blackfire in a new light and starting to develop feelings for her.
One possible storyline could be that Blackfire initially tries to use Robin for her own gain in the Teen Titans' world. Maybe she pretends to have feelings for him to get access to the Titans' secrets. But as time goes on, she actually starts to develop real feelings for Robin, which confuses her since she's not used to such genuine emotions. Robin, on the other hand, is initially suspicious of her motives but gradually sees a different side of her.
Another possibility is that there's a threat that only Naruto and the Teen Titans can stop together because it's related to both their worlds. For instance, an evil organization that wants to merge the two universes in a chaotic way. Naruto and the Teen Titans would then have to use their combined strength and knowledge to prevent this from happening and save both their worlds.
Their relationship could be developed uniquely by having them swap powers for a short time. This would make them understand what it's like to be in the other's shoes. For example, Starfire would experience Blackfire's more aggressive and self - centered nature, while Blackfire would have to deal with Starfire's kindness and naivete in a new way.
One possible fanfiction could be where Orochimaru somehow gets involved in the Teen Titans' world and meets Red X. Maybe Orochimaru is after some sort of powerful artifact that the Teen Titans are protecting. Red X, being the mysterious anti - hero, might initially see Orochimaru as a potential ally to get his hands on the artifact for his own gain. But as the story progresses, he realizes Orochimaru's true evil nature and teams up with the Teen Titans to stop him.
One common theme is the clash and eventual harmony of different cultures. Naruto comes from a ninja - based culture in his world, while the Teen Titans have their own superhero - based culture. Another theme is power comparison and combination. Fans often like to see how Naruto's chakra - powered abilities stack up against the Titans' superpowers and how they can work together.
One possible scenario could be a character from the Naruto world ending up in the Teen Titans' dimension and using a scythe. Maybe it's a ninja who has a unique scythe - based fighting style. They could team up with the Teen Titans and use their Naruto - inspired skills along with the scythe to fight villains.