As a fan of web novels, I can't make predictions or judgments about fictional storylines because it involves subjective bias and emotional factors. At the same time, One Piece and Marvel superheroes were fictional characters with different abilities and settings, so it was difficult to predict the outcome of a battle between people with the same ability. However, if we have to make a judgment, we can take into account the characteristics and abilities of these superheroes. For example, Luffy in One Piece was a powerful fighter with the ability of rubber fruit and dominance. He could move freely in water and air. Iron Man was a technological genius who had all kinds of advanced weapons and technology to fight different enemies in the Marvel Universe. Therefore, if a battle between two people with the same type of ability was to be carried out, the outcome of the battle might depend on the abilities of both parties, battle strategies, external factors, and other factors that could not be easily predicted.
It's really hard to say. Harry Potter has some very powerful magic at his disposal. He could potentially use a spell to send the Hulk to another dimension or something. But the Hulk's raw power is so great. If he got his hands on Harry, it would be over. So, it could go either way depending on how the fanfiction is written.
I think Harry Potter would win. He has a wide range of spells at his disposal and he's very resourceful. He's faced many tough opponents before and has always found a way to come out on top.
It's hard to say for sure. Percy is really powerful with his water powers and his combat skills, but Atlas is a Titan. I think if Percy uses his environment to his advantage, like if there's a lot of water around, he could win.
It's really hard to say. Harry has his natural talent and the power of love on his side. But Snape is a very skilled wizard with a lot of experience. If it's a fair fight in an open area, Harry might have a chance because of his quick reflexes and ability to think on his feet. However, Snape could use his knowledge of the Dark Arts and his sneaky tactics to gain an upper hand.
Saitama would win. Saitama's whole shtick is that he can defeat any opponent with one punch. All For One is powerful in the My Hero Academia universe, but Saitama's strength is on a completely different level. His power is so absurd that it's hard to imagine any character from My Hero Academia being able to withstand his punch.
It's really hard to say. Naruto has the power of the Nine - Tails and years of combat experience. But Boruto is young and full of surprises. He has his own unique skills. I think it could be a tie. They both have strong wills and would not want to seriously harm each other.
I think Steve would win. He has that moral high ground most of the time and is extremely disciplined. In a fight, his strategic thinking would come into play. Bucky, on the other hand, while being a great fighter, might be more impulsive in this situation. Since they are fighting over Tony, Steve could use his charm and the fact that he's seen as a more 'good -guy' figure in general to sway Tony's opinion, which could give him an edge in the fight.
I think Rei might win. She has a certain calm and mysterious allure. Shinji seems to be often drawn to her quiet strength. Asuka's more aggressive approach might actually push Shinji away in the long run, while Rei's gentle, yet persistent, presence could win Shinji over.
It's really hard to say. Draco is young and brash, but he has some powerful spells up his sleeve. Snape, though, is extremely experienced and cunning. He's a master of the Dark Arts and has a lot of knowledge. So if it's a fair fight, Snape might have the upper hand because of his experience.
Sakura. She has shown great strength and determination in the original series. In a fight over Naruto in fanfiction, she would likely use her physical strength and her medical ninjutsu to her advantage. Plus, her strong will would make her not back down easily.