Maybe Naruto's cosmic powers allow him to communicate with celestial beings. These beings could give him prophecies or tasks that he has to complete to maintain the balance between the Ninja World and the cosmos. For example, he could be tasked with preventing a collision between a rogue planet and the Ninja World.
One exciting storyline could be Naruto using his cosmic powers to travel across different dimensions to find a way to save the Ninja World from a new, otherworldly threat. He might encounter strange beings and have to learn to control his new powers in unfamiliar environments.
One possible storyline could be Naruto's mutant power being the ability to control all forms of nature energy without the need for training. This would make him extremely powerful and feared in the ninja world. Another could be that his mutant power is related to instant teleportation, allowing him to appear anywhere in an instant, which would change the dynamics of battles and missions.
Perhaps a story where Naruto's fire powers are not fully under his control at the start. He accidentally sets things on fire and has to go on a journey to learn how to master them. Along the way, he meets an old sage who teaches him unique techniques related to his fire powers.
One interesting storyline could be Bella discovers her ice powers in a moment of great danger. For example, she's in a forest and a wild animal is about to attack her. Suddenly, her ice powers manifest and she freezes the area around the animal, saving herself. Another could be that she joins a group of superpowered individuals and uses her ice powers to help them fight against an evil force that is melting the polar ice caps. She uses her powers to create ice barriers and weapons to combat the enemy.
In Naruto fanfiction, some new powers could be the ability to manipulate time on a small scale. For example, a character might be able to slow down time for a short period during a fight, giving them an edge. Another new power could be the power to control the elements in ways not seen in the original series, like combining lightning and water to create a unique and powerful attack.
One interesting storyline could be that Harry discovers his moon powers during a full moon at Hogwarts. Maybe he can communicate with magical creatures that are only active during the full moon. Another could be that his moon powers are linked to a hidden prophecy, and Voldemort wants to steal those powers for himself.
A more complex storyline could involve Naruto's PTSD affecting his relationships. He might push away his friends and loved ones because he doesn't want them to see his vulnerable side. The fanfiction could then explore how his friends try to break through his walls and help him heal from his past traumas.
In some fanfictions, Naruto might have the power to control time. For example, he could freeze time during battles to gain an advantage. Another impossible power could be the ability to instantly teleport to any location in the ninja world without using any known jutsu. He might also have the power to communicate with all living beings telepathically, which is not part of his original abilities in the official story.
One possible storyline could be that Naruto wears glasses as a disguise while on a secret mission. He might be infiltrating an enemy organization where his usual look is well - known, so the glasses help him blend in. Maybe he also uses them to give off a more studious or intellectual appearance to gain the trust of certain targets.
One interesting storyline could be Naruto gaining the power of time manipulation. He could use it to go back and prevent some of the tragedies in the Naruto universe, like the death of his parents. This would change the entire course of the story and lead to new alliances and conflicts.
Maybe Naruto would have the power of cosmic energy projection. He could shoot out powerful blasts of energy that are a mix of his chakra and cosmic forces. This would be a great offensive weapon against the Avengers' enemies.