In a crossover fanfic, it might start with the Hulk being accidentally transported to the DC Universe where the Justice League exists. His presence would cause chaos at first, but then the League would realize his potential as an ally. They could try to communicate with him, which might be difficult given his limited vocabulary when in his enraged state. But once they do, they could form a powerful alliance against the villains in the DC Universe.
One way it could work is by having a threat that requires both the Hulk's strength and the Justice League's diverse powers. For instance, an alien invasion that has technology to nullify the League's powers partially. The Hulk's physical strength would be unaffected, so he could be the key to victory.
A possible scenario for a Hulk and Justice League crossover fanfic could be that a powerful villain creates a device that can merge different universes. This brings the Hulk into the Justice League's world. The League initially views the Hulk as a threat and tries to subdue him. But as they learn more about his origin and his fight for justice in his own way, they start to work together. The fanfic could then explore how the Hulk's abilities, like his superhuman strength and ability to jump great distances, would complement the powers of the Justice League members, such as Flash's speed or Aquaman's control over the sea.
Well, in this fanfic, the Hulk could bring a new dynamic to the Justice League. His lack of restraint might force the League to adapt their strategies. For example, Batman would have to figure out how to control Hulk's rage. And Wonder Woman might find herself in a position where she has to protect Hulk from his own self - destructive tendencies while also using his power to their advantage. It could be a story full of conflict and cooperation.
Definitely Superman. He has the strength and the moral compass to try and understand the Hulk. He can also withstand the Hulk's attacks to a certain extent, so he could be the first to approach the Hulk and attempt to form an alliance. He might see the good in the Hulk, similar to how he sees the potential for good in Lex Luthor at times.
One possible plot could be that the Hulk is somehow transported to the DC universe and is initially seen as a threat by the Justice League. They might try to subdue him, but then realize he's not entirely a villain. Maybe there's a common enemy that forces them to team up. For example, a powerful alien force that is causing destruction in both the Marvel and DC universes. The Hulk's brute strength combined with the Justice League's diverse powers could make for an epic battle against this enemy.
The combination of Hulk and Superman would be really interesting. You have two extremely powerful beings. Superman's moral compass and the Hulk's uncontrollable rage would create a great dynamic. They could have a friendly sparring match where Superman has to figure out how to hold back the Hulk without hurting him. Or they could team up against a powerful foe, with Superman using his flight and heat vision while the Hulk does his smash attacks.
In a fanfic, it could be that the magic in the Harry Potter world has an unexpected effect on Hulk. For instance, the magic might make Hulk's transformations more controllable, or it could give him the ability to communicate better. And in return, Hulk's super strength and durability could be used to protect Hogwarts from various threats, like a giant dragon attack or an invasion of dark creatures. This way, both elements of the two universes blend well and create an exciting story.
Well, Superman's strength and invulnerability would be a great match against the brute force of some of the larger Warhammer creatures like Ogres or even some of the daemons. His heat vision could also be a useful weapon against hordes of enemies. Batman's strategic mind would be invaluable in dealing with the complex politics and power struggles in the Warhammer universe. He could also use his gadgets to adapt to the different technologies and magics there. Wonder Woman's combat skills and her Lasso of Truth could be used to great effect in dealing with the more devious characters in Warhammer, like the Dark Elves.
She - Hulk's legal background would add an interesting dimension. The Justice League often deals with complex situations that could involve legal aspects. She could help them navigate through any legal loopholes or treaties. For example, if they have to deal with an international incident caused by a supervillain, she could be the one to sort out the legal implications.
In a crossover, Ichigo could bring his own set of moral values. The Justice League has its own code of ethics, and Ichigo's Shinigami code could add a new dimension. His experience in dealing with Hollows and protecting the living could translate well into the Justice League's mission of protecting the world. He might even introduce the concept of soul purification to the League, which could be a unique approach to dealing with certain villains.
Well, it could start with the Hulk being magically summoned to Hogwarts. He'd be confused by all the magic around him. The Hogwarts professors would be both fascinated and worried about this strange, incredibly strong being. They'd try to communicate with him, but the Hulk might just roar in response. Harry and his friends could be the ones to eventually make a connection with the Hulk, maybe by showing him kindness instead of fear.
The experienced members of the Justice League would likely take on a mentoring role. For example, Superman might offer advice to Superboy on how to better control his powers. Batman would probably be more cautious about involving the Young Justice team in dangerous missions, while the younger heroes would be eager to prove themselves. Aqualad could learn new underwater combat techniques from Aquaman. This would create a dynamic of growth and learning between the two groups.