It could be a power that a character from another dimension brings into the My Hero Academia world. This character could be a crossover from the Naruto universe, or it could be a unique creation within the fanfiction. Their Sharingan powers would likely make them a formidable force and would change the dynamics of battles and relationships in the story.
One way it could fit is by having a character with a quirk that allows them to mimic the Sharingan's abilities. For example, they might be able to copy other heroes' or villains' quirks in a similar way to how the Sharingan can copy jutsu in Naruto. This would add a whole new level of strategy and intrigue to the My Hero Academia world.
Gohan could fit in by being a transfer student. His Saiyan powers would be seen as a very unique 'quirk'. In the harem aspect, his kind heart would draw the attention of the female characters. For example, Mina would find his positive attitude infectious.
It can be integrated through a magical artifact. For instance, a mysterious relic is discovered in the My Hero Academia world that bestows the Sharingan upon those who touch it. This could lead to a race among heroes and villains to obtain it.
In a fanfiction scenario, the Hulk might be a result of a secret experiment by the League of Villains to create an ultimate weapon. But instead of being fully controllable, he breaks free and becomes a wild card in the power dynamics of the My Hero Academia world. His presence would disrupt the existing balance between heroes and villains as everyone tries to either control or destroy him.
Goku could be seen as an alien with an extremely powerful 'Quirk' in the My Hero Academia world. His Saiyan abilities like flight, super strength, and energy blasts could be considered a new type of Quirk. He would likely stand out a lot and attract the attention of both heroes and villains.
Sakura Haruno might enter the MHA universe through some sort of multiverse portal. Once there, her strong - willed and determined nature would make her a great hero - in - training. She could learn to use her physical strength, which she had developed in the Naruto world, in combination with a new MHA - style quirk. For example, she could have a quirk that enhances her strength even further when she focuses her chakra (or a similar energy concept in MHA). This would make her a formidable force against villains.
Iron Man's suit could potentially be considered a 'quirk' in the MHA universe. It would be a very powerful one at that. He could use his repulsor beams and various other gadgets to combat villains. Also, his ability to constantly upgrade and improve his suit would make him a formidable force. For example, he could adapt his suit to counter the different quirks of villains, like creating a device to nullify a villain's teleportation quirk.
She could be a transfer student from another hero academy with her own set of unique skills. Her powers would likely make her stand out among the MHA students.
Well, Goku's super strength and his ability to constantly power up could be a huge asset in the My Hero Academia fanfiction world. He could be like an otherworldly hero with his Saiyan powers. His Kamehameha wave would be an extremely powerful quirk - like ability. Maybe he could be a visiting hero from another dimension, coming to help out in the battles against the villains in the My Hero Academia universe.
Well, one way could be that Ichigo arrives in the My Hero Academia world through some sort of interdimensional portal. His powers, like his Soul Reaper abilities, would be seen as a very unique and powerful quirk. He might end up at UA, either as a student or a guest instructor. His strong sense of justice would align well with the values of the heroes in that world.
In fanfiction, Broly might be a villain who comes to the My Hero Academia world seeking a worthy opponent. His raw power would pose a huge threat to the heroes, and they'd have to figure out how to stop him without getting killed.