One potential plot line could be that the villains from My Hero Academia somehow find a way into the Undertale universe. They start causing chaos and trying to take over the Underground. The heroes from My Hero Academia then team up with the friendly monsters in Undertale to fight back. Along the way, they learn about each other's powers and cultures.
A different plot line could involve a character from Undertale ending up in the My Hero Academia world. Let's say Frisk. Frisk could be seen as a new kind of 'quirk - less' hero. They use their determination and the skills they learned in the Underground to help the heroes in My Hero Academia. Maybe they teach the heroes about the power of determination, which could be a new concept in the My Hero Academia universe. This could lead to some of the heroes unlocking new levels of their quirks through understanding determination.
Well, in a My Hero Academia Undertale crossover fanfiction, the characters' abilities could combine in really interesting ways. For example, Deku's One For All could potentially merge with Sans' ability to dodge attacks effortlessly. Deku might gain the power to not only have super strength but also be able to anticipate and avoid attacks like Sans. And Ochaco's zero - gravity power could interact with the gravity - manipulating powers in Undertale. Maybe she could use her power to counteract some of the strange gravitational effects in the Underground world.
One plot line could be Naruto trying to prove himself within the Sitri family. Since he's from a different world with different powers, he might face some skepticism. Another could be a conflict where Naruto has to use his ninja skills to protect the Sitri family from an outside threat in the DxD world. Maybe there's a power - hungry group that wants to take over the Sitri family's territory or resources.
Obviously, Gaster himself is likely to be a main character. His mysterious nature makes him a central focus as readers are eager to learn more about him. Another potential main character could be Frisk. Their ability to reset and influence the game's world could be very interesting when combined with Gaster's enigma. They could either be allies or have some sort of conflict due to their different understandings of the world.
One possible plot could be that the Omnitrix from Ben 10 somehow ends up in the My Hero Academia universe. Ben could team up with Izuku Midoriya. Ben, using his various alien forms, could help in hero battles against villains. For example, Heatblast could be useful against ice - based villains in the MHA world. And Izuku could learn a lot from Ben's experience in handling different powers and situations.
One idea could be a crossover with 'One Piece'. The heroes from 'boku no hero academia' could end up on the Grand Line and have to deal with pirates while also using their quirks. Another is a crossover with 'Naruto'. Maybe the students of UA could train with the ninja in Konoha, learning new skills and sharing their quirk knowledge. A third could be a crossover with 'Attack on Titan', where the heroes have to face the Titans and figure out how to use their quirks to defeat these huge threats.
Well, it could be about the heroes from My Hero Academia getting caught up in the events of Infinity War. Maybe Thanos targets the quirks in the MHA universe. Deku might try to use his One For All to stop Thanos, seeing it as a great evil. And the Avengers could be confused by the existence of quirks at first.
Maybe the plot involves a device created by Stark Industries that malfunctions and creates a portal between the two universes. The heroes from both sides initially have some misunderstandings and fight each other. But then they realize that there is a greater threat. The My Hero Academia students could learn a lot from the Avengers' teamwork and fighting styles, while the Avengers are impressed by the creativity of the quirks. They then join forces to stop a group of villains who are trying to use the portal to invade both worlds.
Well, it could be that Spider - Man gets transported to the My Hero Academia universe. Maybe he teams up with Midoriya. They could learn from each other's powers. Spider - Man could show Midoriya some new ways to use his One For All power, like how to be more acrobatic during battles. And Midoriya could teach Spider - Man about the quirks system in their world.
One idea could be that the Pokemon have Quirks. For example, Pikachu could have an electric - based Quirk that is even more powerful than its normal electric attacks. The heroes in training from My Hero Academia could team up with these special Pokemon to fight against villains who are also using Pokemon with dangerous Quirks. It would be a really cool mix of the two universes.
Stain could be considered as an anti - hero in fanfiction. His extreme views on heroes, while not entirely acceptable, could be delved into deeper. He believes that only true heroes should be recognized and is willing to take extreme measures to prove his point. A fanfiction could explore a different side of him, perhaps one where his actions are more nuanced.