A new character could be an alien or a being from another dimension who accidentally lands in their world. This character could have unique powers or technology that both confuses and helps Big Hero 6. They would have to learn to communicate and work with this strange new addition to their world while also dealing with any threats that come their way.
There could be a new tech - savvy kid who idolizes Hiro and wants to join the team. This character might bring in fresh ideas and a different perspective on using technology for good.
Maybe a future version of an existing character from their past, like Tadashi, brought back in some unexpected way, perhaps as an AI projection with all his knowledge and a new mission for the team. Another potential new character could be a rival scientist who initially opposes Big Hero 6 but later realizes they are on the same side when a greater threat emerges.
Perhaps a mysterious mentor figure appears. This person has seen the rise and fall of many kingdoms and has come to guide Ruby in her fight against the darkness.
Another type of new character could be a mysterious figure who appears in Naruto's future vision. This character might have powers that are beyond comprehension at first. They could be a key to unlocking a new form of chakra or a secret about the origin of the ninja world. Their motives would be unclear at first, adding an element of mystery to the fanfiction.
There could be a healer character. Since Percy is a broken hero, someone with the power to heal his physical or emotional wounds might be introduced. This character could have their own backstory and motives, perhaps being related to an ancient Greek deity of healing in a new and unique way.
There might be a new character who is a tech - genius and uses advanced gadgets to fight crime. They don't have a traditional quirk but instead rely on their intelligence and engineering skills. This would be a fresh take on the types of characters in the story. Also, a character who has the ability to communicate with animals and enlist their help in battles could be really interesting.
There could be their children's friends. Maybe a young ninja from a far - off village who comes to study in the Hidden Leaf. His unique abilities and different cultural background could bring new elements to the story.
Stain could be considered as an anti - hero in fanfiction. His extreme views on heroes, while not entirely acceptable, could be delved into deeper. He believes that only true heroes should be recognized and is willing to take extreme measures to prove his point. A fanfiction could explore a different side of him, perhaps one where his actions are more nuanced.
A young Tauren shaman who has a unique connection to the elements. He could be born with the ability to communicate with a previously unknown elemental spirit. This shaman might lead his people in a new era of peace and harmony with nature.
Well, in addition to the ones mentioned above, Ino could be part of Naruto's harem. She's confident and has her own charm. Then there's also Temari. She's a strong - willed and powerful kunoichi from the Sand Village. Her relationship with Naruto could develop in an interesting way in a harem fanfiction. And don't forget about Karin, who has had some interactions with Naruto and could potentially be in the harem.
There could be the descendants of Jon Snow and Daenerys Targaryen. Their child might be a central figure, having to deal with the complex legacy of their parents. With the blood of Stark and Targaryen, they would have a unique position in the power struggle.
It could be about the team facing new, advanced threats in the future. Maybe a new villain emerges with technology far beyond what they've seen before, forcing them to upgrade their own gadgets and skills.