Beast Boy is another good option. His ability to transform into different animals can bring humor to the fanfiction. He could also be a mediator between Starfire and Blackfire, using his light - hearted nature to ease the tension between the two sisters. His friendship with Starfire can also be explored further in relation to Blackfire.
Often, in Naruto Blackfire fanfiction, Sakura can also be an important character. She might be jealous of the new relationship between Naruto and Blackfire, or she could work together with them. Sasuke may also make an appearance, especially if the story involves some sort of threat to the ninja world that requires his power. So, while Naruto and Blackfire are central, other characters from the Naruto universe play significant roles as well.
One interesting Naruto Blackfire fanfiction could be one where Blackfire teams up with Naruto to face a new and powerful enemy. They combine their unique skills, Naruto's Rasengan and Blackfire's, well, black fire abilities, creating a dynamic duo in the story.
First, you need to create your OC. Decide on their appearance, personality, and backstory. For example, if your OC is a shy alien, it will change how they interact with the bold Blackfire. Then, think about the setting. Is it in outer space? On a different planet? After that, plan out the plot. Maybe they meet during a battle or at a spaceport. Keep in mind the dynamics between Blackfire's character traits and your OC's.
A popular 'Blackfire x OC' fanfic is 'The Redemption of Blackfire'. Here, the OC has a pure heart and tries to bring out the good in Blackfire. The story is filled with emotional moments as Blackfire struggles with her own nature and the influence of the OC. It delves deep into their characters and how they can change each other for the better.
One popular theme is the exploration of their sisterly relationship. It could be about them reconciling after past differences. Another theme might be their different powers and how they interact in various situations. For example, they could team up against a common enemy using their unique abilities.
Another plot could involve a power exchange. Blackfire's technology-based powers somehow interact with Naruto's chakra, and they have to figure out how to control this new combined power. They might start training together, with Naruto teaching Blackfire about chakra control and she teaching him about advanced alien combat strategies.
One common theme is friendship. Naruto is known for his ability to make friends, and in fanfiction with Blackfire, they might form an unlikely friendship. Another theme could be power - sharing. Blackfire has her own set of powers, and Naruto with his ninja skills, and they could exchange knowledge about their powers.
It really depends on the situation. Naruto has his powerful ninjutsu and the ability to tap into the Nine - Tails' chakra. But Blackfire has her superhuman strength, energy projection, and advanced alien technology. In a long - range fight, Blackfire might have the advantage with her energy blasts. However, if Naruto gets close enough, his taijutsu skills combined with his chakra - enhanced attacks could be very dangerous for Blackfire.
I'm sorry, but 'lemon' often refers to adult - themed fanfiction, which is not appropriate. However, I can recommend some general Naruto and Blackfire fanfiction. You can try searching on fanfiction - dedicated websites like Archive of Our Own or FanFiction.net. Just look for stories that focus on their interactions, character development, and adventures within the Naruto universe.