One idea could be a plot where the Avengers and DC heroes are brought together by a powerful cosmic entity that threatens both universes. They have to combine their powers and strategies to defeat it. For example, Superman and Thor could work together to take on the entity's brute strength while Batman and Iron Man figure out its weaknesses using their intellect.
A great concept might be a crossover tournament. Heroes from both the Avengers and DC are pitted against each other in a series of battles. But as the tournament progresses, they realize there's a hidden villain behind it all, trying to use the chaos to take over. So they end up joining forces to stop this real threat.
A cool dc superheroes crossover fanfiction could involve Wonder Woman and Aquaman. They could discover an ancient underwater civilization that has a connection to the Amazons. As they explore this link, they face off against some sea - based villains and also have to deal with the political tensions between the surface world and Atlantis.
Another interesting concept is a crossover of Wonder Woman and Aquaman. They might come together when an ancient underwater and Amazonian artifact is stolen. The story could explore their different cultures as they travel across land and sea to retrieve the artifact and prevent it from being used for evil.
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.
A cool dc marvel crossover fanfiction might involve Batman and Iron Man. Picture Batman being intrigued by Iron Man's high - tech gadgets and the two of them collaborating to create an even more advanced piece of technology to defeat a new breed of super - criminals that are using alien and advanced Earth - based tech.
Maybe Deadpool could team up with Harley Quinn. Their personalities are both wild and unpredictable. They could go on a rampage through Gotham, with Deadpool constantly breaking the fourth wall and Harley just being her crazy self, driving the Batfamily nuts as they try to figure out how to deal with this odd couple.
Well, in an 'ichigo and dc crossover fanfiction', perhaps Ichigo's Hollow powers could be mistaken for some kind of new meta - human ability in the DC universe. The Justice League might initially view him as a threat and try to contain him. But then, when they realize he's there to fight a greater evil, like Darkseid who has somehow tapped into the spiritual energy of Ichigo's world, they join forces. Ichigo could also share his knowledge of the afterlife with characters like Constantine, which could lead to some really interesting storylines.
One idea could be that the Hulk somehow gets transported to the DC universe. Maybe due to a freak accident involving some sort of interdimensional portal created by Lex Luthor in an attempt to bring in a powerful being to defeat Superman. The Hulk then starts rampaging through Metropolis, and Superman has to figure out how to stop him without causing too much destruction himself. He tries to reason with the Hulk at first, but when that doesn't work, he has to use his strength and speed to keep the Hulk occupied until they can find a way to send him back to his own universe.
A cool concept could be that Vegeta gets transported to Gotham City. He initially clashes with Batman due to their different methods, but they eventually work together to take down a powerful new enemy that is a threat to both their worlds.
One idea could be a story where the Avengers and the Justice League team up to fight a common cosmic threat like Darkseid and Thanos working together. It would be a battle of epic proportions with heroes from both universes having to put aside their differences and combine their powers.
One idea could be Master Chief getting transported to the DC universe and teaming up with Batman. They could combine their combat skills and strategic thinking to take on a common enemy like Darkseid.