The Pink Ranger could be an interesting character to pair with the Black Ranger. Maybe they have a love - interest kind of relationship where their different personalities clash at first but then they grow to understand and care for each other. Also, a villain who has a personal vendetta against the Black Ranger could be paired with him in a story. This would create a lot of tension and conflict, making for an exciting plot.
A great plot might involve the Black Ranger getting lost in a different dimension while on a mission. In this dimension, he has to adapt to new rules and powers while trying to find his way back. He could meet new allies or face enemies that are unique to that place. Also, a plot about the Black Ranger having to train a new recruit who has a lot of potential but also a lot of recklessness could be interesting.
She could be from a hidden clan. Maybe her clan was in charge of protecting a powerful and ancient artifact. But when the Nighloks started getting more aggressive, her clan decided it was time for her to join the Power Rangers. Her skills with the katana, which she learned from her clan's strict training regime, would be a great asset to the team.
Her powers could be more focused on stealth. While the other rangers are great at direct combat, she can move silently and strike without being noticed. For example, she might be able to turn invisible for short periods, which would give her an edge in surprise attacks.
Another storyline might involve the Black Ranger having to train a new recruit who has a lot of potential but also a wild streak. This could show the Black Ranger's leadership skills as he tries to mold the recruit into a proper Power Ranger. It could also have some comical moments as the recruit gets into various scrapes.
First, start with his flaws. Maybe he's too impulsive at times. Then, have him face situations where this impulsiveness gets him into trouble. As he realizes his mistake, he can start to work on being more patient. For example, in a battle, his quick actions might lead to a teammate getting hurt. This makes him reevaluate and grow.
One possible love story could be that Jayden meets a new ranger from another team during a joint mission. They start off as comrades but gradually realize their feelings for each other as they face various challenges together. Their love blossoms as they support one another through tough battles against powerful enemies.
Another idea is a character swap. Picture Naruto as a Power Ranger Samurai. He would bring his ninja skills and determination to the team. His Rasengan could be transformed into a special attack for his Samurai Zord. Or, a Power Ranger Samurai could be sent to the Naruto world and have to learn ninja techniques to survive and help the village.
One idea could be the Black Ranger getting lost in a parallel dimension. He has to use his skills and wits to find his way back home while facing new enemies and making unexpected allies. Another plot could involve him losing his powers temporarily and having to rely on his martial arts training to protect the city.
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.