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.
A young Twi'lek who discovers she has strong Force - powers could be a new hero. She might come from a planet where Force - users are persecuted and has to fight for her right to exist and learn the ways of the Force. Another could be a human - clone hybrid. He has the best of both worlds, the combat skills of a clone and the creativity and adaptability of a human. He could use these skills to bring peace to the galaxy. And a droid with advanced artificial intelligence that develops a sense of morality and fights for justice in the galaxy could also be a new hero.
Another plot could involve the return of an ancient evil that was thought to be long gone. This evil could be related to the Old Gods and start corrupting the land and the creatures in it. The heroes would then have to unite all the factions, including the Horde and the Alliance, to fight against this common threat. It could lead to some interesting character development as they put aside their differences.
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 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.
There could be a wise old wizard who becomes Kaneki's mentor in the new world, guiding him on how to use the magic there.
Maybe there's a group of dark ninjas who are trying to resurrect an ancient evil. They see Naruto and Hinata as the biggest threats to their plan, so they constantly try to attack them and disrupt their lives. These dark ninjas could have some powerful and forbidden jutsu.
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.
Thor could be a potential hero. As Loki's brother, he would likely sense that something is wrong and set out to find and rescue Loki.
Alice could be a crucial hero. Her ability to see the future could help in planning the rescue. She could foresee any traps or ambushes set by Aro and guide the others to avoid them. Also, her friendship with Bella would make her determined to save her from Aro's clutches.