There could be a character who represents the scientific community in this fanfiction. They might be skeptical at first about the OC's plant powers but later become an ally. They could help the OC understand the scientific aspects of their powers, like how the plants are able to respond to the OC's commands on a cellular level.
Often, there might be a villain. This could be someone who wants to use the power of the plants for evil, like a dark sorcerer who wants to drain the life from the plants to gain more power for themselves. And of course, there would be friends of the OC, maybe other people with different powers who team up with the OC to protect the plant - powered world.
Perhaps the OC with plant powers has to defend a magical garden from dark forces. The plants could transform into warriors or create barriers to keep the intruders out. It could be a story full of action and magic.
Obviously, Dipper is the main character as the title implies. His sister Mabel is often included too. She might react in various ways to Dipper getting powers, like being excited or a bit jealous. Wendy is also a common character. She could be a source of support or a love interest for Dipper in some fanfictions.
In this kind of fanfiction, aside from the OC, you'll often see other young trainers. They could be traveling companions or just other kids starting their Pokemon adventures. Legendary Pokemon might also make an appearance. For example, Mewtwo could be involved, either as a friend or a foe to the OC, depending on the story's direction. There might also be a Team Rocket - like group causing trouble for the OC and other characters in the Pokemon world.
Kakashi could be paired with Naruto as well. Kakashi, with his wealth of knowledge and experience, could guide Naruto in using his new and different powers. For instance, if Naruto obtains the power of space - time ninjutsu similar to Kakashi's Kamui, Kakashi could teach him how to use it effectively and avoid its potential drawbacks.
The OC's powers could be developed through training with a Lucario. Since Lucario are known for their control over aura, they could teach the OC how to focus and strengthen their own aura-based powers. For example, by sparring with the Lucario, the OC can learn new attack techniques and improve their speed and strength.
Batman himself is obviously a common character. Then there are often female characters like Catwoman. She is a complex character with her own motives and her relationship with Batman is always full of tension. Batgirl is also frequently included. She is strong - willed and has her own sense of justice. Another one could be Harley Quinn. Her chaotic nature can add a lot of interesting dynamics to the harem.
In some fanfictions, Eldar characters might be paired with a Necron Lord OC. This creates an interesting dynamic as the Eldar are a very different and ancient race. They could be either enemies, with the Necron Lord OC seeing the Eldar as a threat to their plans, or they could form a tenuous alliance based on a shared goal, like stopping a Chaos incursion.
Often, there are original characters created specifically for the fanfiction. These OCs are the main focus with their dark quirks. There might also be some canon characters from the original work that the fanfiction is based on. They could be friends, foes or mentors to the OC. For example, if it's a fanfiction based on a superhero story, there could be a well - known hero who tries to help the OC control their dark quirk.
Many fanfictions feature original characters with the plant bloodline. These characters can be designed to have unique personalities and backstories related to their bloodline. They might be outsiders who come to the Hidden Leaf Village and introduce new plant - based jutsu, or they could be descendants of a long - lost clan with a powerful plant bloodline.
In 'naruto plant manipulation fanfiction', some original characters created by fans also become popular. These are often characters that are designed specifically to have strong plant manipulation abilities. They can bring new storylines and interactions to the Naruto universe. Also, Sakura could be a popular character in this regard. While she doesn't have plant manipulation in the original, in fanfiction, she could be given this power and it would add a new dimension to her character, like using plants for medical research and treatment.