One idea could be to have the Naruto characters end up in the Power Rangers Ninja Steel universe. They could learn about the Ninja Steel powers and use their own ninja skills in combination. For example, Naruto's shadow clone jutsu could be used in a creative way during battles against the villains in the Power Rangers' world.
Conner, another member of the Dino Thunder team, is a great character to pair with the Green Ranger. They could have a friendly rivalry that turns into a strong friendship as they face challenges together. Their different personalities, with Conner being more impulsive and the Green Ranger perhaps more reserved, would create an interesting dynamic.
One interesting storyline could be the Green Ranger OC coming from a different dimension where the rules of power are different. They have to adjust to the new team while also bringing in their unique combat skills. For example, they might have a special way of summoning their zord that the other Rangers have never seen before.
One possibility could be that her fellow Power Rangers would become extra protective. They might go on a more aggressive hunt for the villains responsible, fearing for Hayley's safety and their team's future without her full strength. Maybe they'd also bring in some new tech or powers to make sure she can heal quickly and be back in action.
Good writing quality, of course. This includes proper grammar, vivid descriptions, and a smooth flow of the story. A fanfiction that can make you feel like you're right there with the Power Rangers in their battles and adventures is a great one. For instance, when the writer describes the action scenes in detail, it makes the whole reading experience more exciting.
You can start by looking on fanfiction websites like FanFiction.net or Archive of Our Own. These platforms have a large collection of Power Rangers Ninja Steel fanfictions. Just use the search bar and type in 'Power Rangers Ninja Steel' and you'll get a bunch of results.
One idea could be to have the Ninja Steel Rangers cross over with the original Mighty Morphin Power Rangers. They could team up to fight a common enemy that is too powerful for either team alone. Maybe Lord Zedd and Galvanax form an alliance, forcing the two ranger teams to combine their powers and zords in new and creative ways.
Consider their backstory. They could be an outcast from their own planet who was found and trained by an old, retired Power Ranger. Their alien origin gives them a different perspective on things. Also, their suit design can be unique. Instead of the regular green, it could have some blue accents or different symbols that represent their individuality.
One great storyline could be the Black Ranger having to face a new, powerful enemy alone. Maybe he gets separated from the rest of the Power Rangers and has to rely on his own ninja skills and inner strength to survive and defeat the foe. Another could be a story where the Black Ranger discovers a new power within himself that has been dormant all this time. It could be a power that has a connection to an ancient ninja legend, and he has to learn to master it while also dealing with the regular threats the Power Rangers face.