Definitely The Flash. Their powers are quite different. The Flash's super - speed could be an amazing contrast to Deku's more physical - based quirk. Deku could learn about time - related concepts from The Flash, and they could have an interesting dynamic when it comes to chasing villains.
In a deku dc crossover fanfiction, perhaps Deku's quirk could be misinterpreted as a meta - human ability in the DC universe. The Justice League might initially be suspicious of him but then realize his pure heart and strong sense of justice. He could also share his knowledge of hero training and strategy with the younger heroes in the DC world like Robin.
Another idea is that Greninja gets exposed to some kind of meta - human - creating substance in the DC universe and gains new powers. It could then join the Teen Titans, sharing its unique Pokémon abilities with the group. It would be interesting to see how Greninja interacts with characters like Robin, Starfire, and Cyborg, and how it uses its powers in battles against the Titans' enemies.
One possible plot for a Deku Iron Man fanfiction could involve a threat that neither hero can face alone. The villains could be creating a device that combines the technology of the Marvel universe with the quirks of the My Hero Academia world. Deku and Iron Man would have to team up, using their respective skills and powers. Deku's agility and experience with his quirk, combined with Iron Man's high - tech weaponry, would make for a great story.
One common theme is the idea of Deku being thrust into unexpected situations where he has to deal with multiple romantic interests from different crossovers. Another theme is the growth of Deku as a character as he navigates these complex relationships.
Maybe there's a multiverse event that causes Peter Parker to be transported to the DC universe. He meets Superman first, and Superman is initially a bit wary of this strange new hero with spider - powers. But as they face a common enemy, like Lex Luthor who has somehow gotten his hands on some Oscorp tech, they learn to work together. Peter can use his scientific knowledge from his own world to help Superman figure out how to disable the dangerous tech.
Well, first, a good DC crossover fanfiction has to have interesting character interactions. For example, seeing how Batman would react to meeting Wonder Woman for the first time in a new context. Second, a unique plot. Instead of the typical 'save the world' plot, it could be something like the heroes having to solve a mystery that involves different dimensions. Third, accurate portrayals of the characters. If Superman is in it, he should still be the big - hearted, powerful hero we know.
One idea could be a crossover with a shonen manga like 'Naruto'. Deku could meet Naruto and they could train together, sharing their different combat styles and ideals. Another could be a crossover with a magical girl manga, where Deku has to adapt to a world of magic instead of his usual quirk - based battles.
Definitely Naruto and Superman. They are both iconic characters in their respective universes. Their different power sets make for an interesting comparison. Another popular crossover is between Sasuke and Batman. They both have a dark and brooding side. And of course, Sakura and Wonder Woman. The contrast between Sakura's ninja skills and Wonder Woman's superhuman abilities is appealing.
Another one to check out is 'Justice League meets Camp Half - Blood'. In this fanfic, the Justice League discovers Camp Half - Blood. It's cool to see how Batman would interact with Chiron, or how Wonder Woman would view the demigod powers. There are a lot of great character moments as the two very different universes collide.