Another approach is to do a Halloween party at UA High. Everyone dresses up in different costumes. Deku could go as All Might in his younger days. There could be a costume contest, and some characters might use their quirks to enhance their costumes. But then, a real threat shows up disguised as a party guest, and the students have to use their wits and powers to stop the danger while still in their party get - ups.
A different idea is to set the story in a parallel universe where Halloween is a time when quirks go haywire. The heroes and villains have to deal with their powers acting unpredictably. Bakugo might accidentally set off explosions more often than usual. They all have to work together to find a way to stabilize their quirks before the chaos gets out of hand.
One idea could be that during Halloween, the villains use the spooky season as a cover to carry out a major heist. The heroes have to figure out their plan while also dealing with all the Halloween chaos in the city. For example, there could be trick - or - treaters getting in the way and the villains using Halloween decorations to hide their traps.
One cool quirk idea could be 'Shadow Mimicry'. The user can blend into any shadow and move freely within the shadow realm, also being able to mimic the actions of those whose shadows they are in. It gives a lot of stealth and surprise attack possibilities in a fanfiction.
Another great story could involve All Might and Captain America. Picture them meeting and sharing their ideals about heroism. They could train together and exchange combat techniques. Then, they face a threat that requires both their strength and leadership. For example, a new super - villain that has the powers of both the quirks from My Hero Academia and the super - powers from Marvel.
One idea could be that Godzilla arrives in the My Hero Academia world during a major villain attack. The heroes initially see Godzilla as a threat but soon realize that he is targeting the same villains who are causing environmental destruction. His massive size and power could be a game - changer in the battle.
First, create a unique Halloween - themed villain. Maybe a villain who can turn into different spooky creatures like a werewolf or a vampire using their quirk. Then, put the heroes in a situation where they have to figure out the villain's weakness. For example, if the villain turns into a werewolf, they might be weak to silver. This creates an engaging mystery for the heroes to solve.
Maybe the new home is a large treehouse - like structure built in a forest. It would blend in with the natural surroundings and provide a peaceful yet secure place for the heroes. They could have different levels for different functions, like a training area on the lower levels and sleeping quarters on the upper levels. It could also be a place where they can study and analyze the quirks of villains and come up with counter - strategies.
Another concept is that Todoroki was turned into a vampire by a villain's quirk gone wrong. He then has to find a way to reverse it. He teams up with Midoriya, who is determined to help his friend. They search for a mysterious old hero who might know a cure, all while Todoroki battles his inner vampire nature.
One idea could be that Kakashi is somehow transported to the My Hero Academia world. He could become a teacher at UA, using his ninja skills and wisdom to train the students in new and unique ways. His Sharingan would be a very interesting power in the MHA universe.
One idea could be a story where Yui Kodai discovers a new quirk ability within herself during a tough battle. Maybe she's able to use her size - changing quirk in a completely unexpected way that turns the tide of the fight.
One plot idea could be that the Saiyan OC is mistaken for a new type of villain at first. As they try to prove they're not a threat, they start to make friends and learn about heroism. Another idea is that they discover a connection between Saiyan powers and some of the hidden secrets in the MHA world. Maybe there's an ancient power source that only a Saiyan can unlock.