One new ability could be the power to heal quickly like some mutants. This would make him even more resilient in battles. He could also have the power to sense danger from a much greater distance. And perhaps he could have the ability to fly, not just by swinging on webs but by using some sort of mutant - based flight power. This would change the way he moves around the city and approaches crime - fighting.
If Spider - Man had mutant powers in fanfiction, his origin story might be different. Instead of being bitten by a radioactive spider, he could be born with his powers. This would change his relationship with the scientific community. For example, he might not be as interested in science as the original Spider - Man. His powers could also be more uncontrollable at first, leading to different challenges in learning to use them.
One possible new power could be energy projection. He could shoot out webs of energy instead of just the physical webs. This would not only enhance his offensive capabilities but also give him a new way to interact with his surroundings and immobilize foes from a distance.
One new ability could be ice - skating at super - speeds. He could glide across water or land, using his ice - skates made of pure ice, and quickly reach his destination or dodge attacks. It would be like a combination of his natural athleticism and his new ice powers.
Another ability could be dark energy projection. Naruto could project bolts of dark energy from his hands or body. This energy could be used to blast away enemies or even to corrupt other things it touches, like sealing jutsu or barriers. It would be a very different and more sinister form of attack compared to his normal Rasengan.
Well, Naruto could gain the ability to heal in a more advanced way. Just as the avatar can sometimes use their connection to the elements to heal, Naruto might be able to do the same with his chakra. He could also have the power to merge with the natural world around him, similar to how the avatar can connect with nature. This would give him an edge in stealth and surprise attacks. Plus, he could develop a new form of sensing, being able to detect not just chakra but also the energy of the elements around him.
In fanfiction, Spider - Man could gain the power of teleportation. This would allow him to quickly move around the city and reach crime scenes faster. He might also develop the power of super strength in his legs, enabling him to jump much higher and farther than before. Additionally, the power to manipulate time, even if just for a few seconds, could be a great addition.
He could have the ability to perform kido, which are the spells used by Soul Reapers. This would give him a whole new range of offensive and defensive capabilities. He might also be able to use bankai, a super - powerful form of his zanpakuto. His new powers could include enhanced spiritual perception, allowing him to sense things that normal ninjas can't, like the presence of Hollows or spiritual disturbances.
One new ability could be the power to charge his own body with kinetic energy for enhanced physical attacks. He could deliver punches or kicks that explode on contact, similar to Gambit's charged staff strikes. Another ability would be to create energy barriers by rapidly charging the air around him. This would be a great defensive move, something Naruto currently lacks in his regular skill set. He could also potentially use Gambit's power to sense the energy levels of his enemies from a distance, giving him an advantage in strategizing his attacks.
Naruto might gain the ability to tap into a primal energy within him due to his wrath powers. This energy could allow him to heal faster when injured in battle. Also, he could have the power to influence the emotions of his enemies. When they look into his eyes during his wrath - filled moments, they could be filled with fear or hesitation. Additionally, his physical attacks could carry a sort of 'wrath - curse' that weakens his opponents over time as they are continuously exposed to his wrath - powered strikes.
Perhaps Doctor Octopus. But instead of just having mechanical arms, his mutation gives him the ability to control any metal object in the city. He wants to take over the city using his newfound powers and sees Spider - Man as the only obstacle.