A cool concept for a'manga deku crossover fanfiction' would be a crossover with 'Fullmetal Alchemist'. Deku could find himself in a world where alchemy is the main form of power. He'd have to figure out how his quirk works in this new setting. He might meet Edward and Alphonse Elric and together they could work on solving the mysteries of both their worlds. For example, Deku could help the Elrics with their search for the Philosopher's Stone using his quick thinking and combat skills, while they could teach him about alchemy.
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.
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.
One interesting idea could be the exploration of Deku's powers from a new perspective. Since the character is reborn, perhaps they gain an enhanced understanding of One For All or develop new ways to use it more effectively. Another idea might be the relationships with other characters. The reborn Deku could form different bonds, like a closer friendship with Bakugo early on, changing the dynamics of their story.
A possible plot is that Villain Deku has a plan to destroy a major hero institution, and Hero Deku has to stop him. But when they meet, Hero Deku realizes that Villain Deku was once like him, full of hope. This makes Hero Deku hesitant to fight at full force. Or perhaps Villain Deku has kidnapped someone close to Hero Deku, and during the rescue mission, Hero Deku tries to convince Villain Deku to change his ways. Also, they could be from alternate universes where the roles are reversed, and they are forced to interact and learn from each other.
One interesting idea could be a crossover with "Moana". Elsa's ice powers and Moana's connection to the ocean could create a really cool dynamic. Maybe Elsa accidentally freezes part of Moana's ocean and they have to work together to fix it. Another could be with "Tangled". Rapunzel's long hair and her adventurous spirit combined with Elsa and Anna's journey in Frozen 2 would be exciting. Rapunzel could use her hair to help them climb mountains or cross chasms. A third idea is a crossover with "Beauty and the Beast". Belle's love for books and knowledge could help Elsa understand more about her powers and the history of magic in the Frozen world.
One idea could be that they are paired for a special project at school. During the project, they discover new sides of each other. Deku could be impressed by Momo's intelligence and strategic thinking, and Momo could be inspired by Deku's determination. This could lead to a growing friendship that might develop into something more over time.
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.
One idea could be to have the main characters from the anime and manga meet in a new region. For example, Ash from the anime could encounter Red from the manga. They could team up to face a powerful new villain that neither has faced before. Another idea is to explore how the different Pokemon-catching mechanics in the anime and manga could interact. Maybe the Pokeballs in the manga have a different effect in the anime world.
Well, a possible plot could be that Dabi and Villain Deku form an alliance to expose the seedy underbelly of the hero world. They could start by causing small disruptions and leaving clues that point to a bigger conspiracy. Along the way, they might have to face other villains who don't want their plan to succeed. Also, there could be a love - hate relationship between them, where they constantly bicker but deep down care for each other's well - being in this dangerous game they're playing.
Perhaps Deku discovers a dark secret about the origin of quirks and decides that the world would be better off without them. So, he starts a villainous campaign to eradicate quirks. He could form an alliance with other outcasts who have been mistreated due to their lack of quirks or abnormal quirks.
Well, a great plot could involve Deku using his dragon quirk to explore a hidden realm full of dragon - like creatures. He could learn about the origin of his quirk there. Or perhaps his dragon quirk has different forms, like a water - breathing dragon form for when he's near water, and he has to master switching between forms in battles.