Character relationships are always a big draw. In fanfictions such as 'Friendship Across Universes', the friendships and rivalries that form between the characters are engaging. For example, Supergirl and Deku might start as rivals, but as they get to know each other, they develop a mutual respect and a strong friendship that drives the story forward.
The cultural differences between the two universes also make for great plot points. For instance, in 'Cultural Exchange Heroes', the characters from the two different worlds learn about each other's cultures. The DC girls are introduced to things like the hero academies in My Hero Academia, and the My Hero Academia characters learn about the more global scope of heroism in the DC world.
Often, the clash of different power systems is very interesting. In some fanfictions, like 'Power Showdown', the DC Superhero Girls' more 'traditional' superpowers contrast with the unique Quirks in My Hero Academia. This leads to some really cool battle scenes.
One popular 'dc superhero girls my hero academia fanfiction' is 'The Meeting of Two Worlds'. It's really exciting as it brings together characters from both universes in a unique way. The author does a great job of making the interactions between the DC Superhero Girls and the My Hero Academia characters believable.
One interesting plot point is the clash of power systems. In these fanfics, seeing how stands from JoJo's interact with quirks in My Hero Academia can be really exciting. For instance, how would a stand user deal with a villain whose quirk nullifies physical attacks? Another is the cultural differences between the two universes. The more flamboyant and often morally ambiguous nature of JoJo's characters compared to the more straightforward hero - and - villain setup in My Hero Academia creates a lot of tension and interesting character dynamics.
The web novel often delves into unique hero - villain interactions that aren't as fully explored in the main series. There are situations where heroes and villains have to team up temporarily, which creates a lot of moral and ethical dilemmas for the characters. This makes for some really engaging storytelling.
A great plot might be a training exchange. The heroes from My Hero Academia go to the DC universe to train with Superman and Batman. They learn different combat and strategic techniques. In return, they teach the DC heroes about quirks. This could lead to some really interesting character interactions. For instance, Bakugo might have some intense sparring sessions with Wonder Woman, and both would learn from each other.
I think Uraraka and Green Lantern would be a cool pairing. Uraraka's quirk allows her to manipulate gravity, and Green Lantern's power ring is based on willpower and can create constructs. They could combine their powers in really creative ways. Uraraka could make objects weightless for Green Lantern to use in his constructs more easily, and he could protect her while she focuses on using her quirk.
Maybe a crossover with the Justice League. The DC Superhero Girls look up to the League, and in this fanfiction, they could be called upon to help when the League is incapacitated by a powerful magic spell. It would be a chance for the girls to prove themselves on a bigger stage.
A really interesting plot idea could be that Strange's magic starts to seep into the My Hero Academia world, causing some quirks to mutate in unexpected ways. Maybe a character like Todoroki suddenly has his fire and ice powers combined in a new, magical way because of the influence. Another idea is that the Infinity Stones somehow end up in the My Hero Academia universe and the heroes have to figure out how to keep them safe from villains.
A darker plot idea could involve a powerful villain who has somehow found a way to corrupt both universes. This villain uses the technology and powers from both My Hero Academia and the Justice League's worlds to create a doomsday scenario. The heroes must put aside their differences and combine their strengths to stop this new threat. This would involve a lot of character development as they learn from each other's methods of heroism and sacrifice.
A plot twist could be that the Quirk system and Stands are somehow related. Maybe there was an ancient event that split the power into two forms. This would open up a whole new exploration of the lore in both universes. Characters would have to reevaluate their understanding of their own powers and how they interact with those from the other universe.
A really interesting plot twist could be that the symbiote from the Spider - Man universe attaches itself to a major villain in My Hero Academia. This would make the villain even more powerful and unpredictable. The heroes would have to figure out how to deal with this new threat that has a combination of a quirk and the symbiote's abilities.