Well, if Izuku had a symbiote in My Hero Academia fanfiction, it would completely change his power dynamics. Firstly, his physical abilities would be enhanced significantly. He could move faster, jump higher, and have greater strength without fully relying on One For All. The symbiote might also give him new combat skills like the ability to create weapons from its own form. This would make him a more versatile hero in combat situations, able to adapt to different types of villains more easily.
He would likely have enhanced strength. The symbiote could augment his natural physical strength, allowing him to lift heavier objects and deliver more powerful punches. His speed would also increase. With the symbiote, Izuku could move at a much faster pace, making it easier for him to dodge attacks and close in on opponents quickly.
His relationship with Bakugo would likely change significantly. Bakugo might initially be jealous of Izuku's unique shadow quirk. But over time, they could develop a more competitive but respectful relationship, as Izuku's shadow quirk gives him new ways to fight. With his friends like Uraraka, Izuku's new quirk could make him seem a bit more mysterious. Uraraka might be curious about how his quirk works and they could bond over her trying to understand it.
Izuku would likely become more serious and determined. The loss of his mother would be a huge blow, but it could also harden his resolve to succeed as a hero. He might be less hesitant in dangerous situations, as he has already faced the worst kind of personal loss.
It probably changes the power dynamics. With Izuku being godlike, he might be able to defeat villains much more easily than in the original, which could change the overall plot progression.
Well, his relationship with Bakugo would likely change a great deal. If Izuku is not human, Bakugo might view him as even more of an oddity or a threat. Instead of just seeing him as a rival with a quirk, he could be more hostile or overly cautious around Izuku.
In a fanfiction where All for One raises Izuku, Izuku's quirk development might take a different turn. All for One could potentially train Izuku to use his quirk in more devious ways. He might also give Izuku additional powers or abilities that are not part of his original quirk. This would make Izuku a very different kind of threat in the My Hero Academia universe. His presence would be a major disruption to the balance between heroes and villains, and the story would revolve around how the other characters deal with this new, All for One - influenced Izuku.
The Izuku Luck Quirk in fanfiction could also impact his training at U.A. His luck might make him find rare training materials or encounter mentors who were not part of the original story. This could accelerate his growth as a hero. Moreover, his relationships with classmates could be different. His luck could make him seem more mysterious to his peers. Some might be jealous of his quirk, while others might be curious and want to team up with him more often. This would lead to a different dynamic within Class 1 - A.
There could also be a more serious - minded interaction. In the face of a great threat, Izuku and Pixie Bob might need to work together closely. They would communicate effectively, with Izuku using his strategic mind and Pixie Bob her combat experience. Their interaction would be focused on the mission at hand, like protecting civilians or taking down a dangerous villain.
The overall theme of the story can shift in izuku all for one fanfiction. The original My Hero Academia focuses on the growth of a hero with a 'good' power. But with Izuku having All for One, the themes of redemption, the nature of power (whether it's inherently good or bad), and the idea of breaking free from the expectations associated with a particular power become more prominent.
The Infinity Gauntlet would likely cause chaos. In My Hero Academia, society is built around the concept of Quirks and how they are used. If the Infinity Gauntlet entered this world, it would introduce a new form of power that is not based on genetics but on an external, extremely powerful object. This would disrupt the existing balance between heroes and villains. Villains might see it as a way to finally achieve their goals of domination, while heroes would have to figure out how to deal with a power that is far beyond what they are used to facing.