One interesting plot twist could be that Izuku initially struggles to control the All For One quirk. Since it's a very powerful and complex quirk, he might accidentally absorb quirks from his friends or allies, causing a rift between them. For example, he could absorb Uraraka's zero - gravity quirk and she feels violated. Another plot twist could be that the League of Villains, thinking Izuku is now one of them because of the All For One quirk, try to recruit him. Izuku has to pretend to go along with them to gather intelligence, but it becomes a dangerous game as he risks being corrupted by their ideology.
A great plot twist could be that the All For One quirk in Izuku has some sort of hidden ability. Maybe it can reverse quirks, so instead of taking quirks, it gives quirks to others. This could lead to a whole new dynamic where Izuku becomes a sort of 'quirk giver' and has to deal with the chaos that ensues. Or perhaps the quirk has a connection to the first user of One For All that no one expected. It could be revealed that the two quirks were once one and the same, and Izuku has to figure out how to use this knowledge to defeat the real villains in the BNHA world.
Well, perhaps a major plot twist could be that Izuku's All for One quirk is actually a modified version created by some secret organization. This organization wants to use Izuku as a weapon. As he uncovers this truth, he has to not only deal with the power of the quirk but also fight against the organization that manipulated him into having it. This would add a whole new layer of mystery and danger to the fanfic.
A great plot could be that a hero with a one - punch quirk loses their memory and forgets how to control their power. They start causing chaos by accidentally punching things and people. Their friends in the hero community then try to help them regain their memory and also teach them new ways to use their quirk more effectively, all while dealing with various villains who see this as an opportunity to take over the city.
A plot for this fanfic could be that Izuku discovers his sand quirk at a crucial moment during a battle. From then on, he starts to train intensively with it. The story could focus on his growth as a hero with this new quirk. He might have to participate in special training sessions designed for quirks like his. There could be a tournament arc where he shows off his new abilities. However, he also has to deal with the fact that some people are skeptical of his sudden change in quirk, and he has to prove himself not only to his enemies but also to those who doubt him.
A fanfic with Izuku having a sand quirk could explore his new power dynamics. He would have to adapt his fighting style completely. Instead of using his original strength - based moves, he'd rely on the versatility of the sand. He could potentially use the sand to travel, like surfing on it. His relationship with other characters might also change. For instance, Bakugo might be even more envious of this unique quirk. And Izuku would have to learn how to use it subtly, perhaps by creating small sand particles to gather information without being noticed.
One idea could be Izuku struggling to control the All for One quirk at first. He might accidentally absorb quirks he doesn't want, leading to chaos. For example, he absorbs a quirk that makes him grow extra limbs and has to figure out how to hide it. Another could be that villains target him more, thinking he'll be easy to corrupt with such a powerful quirk.
One idea could be a hero with an illusion quirk who uses it to create false distractions during battles. For example, making the villains see an army of heroes when there are really only a few, causing them to waste their attacks and energy.
One possible plot twist could be that Izuku suddenly loses his powers right before the wedding. This would add a lot of drama as they have to figure out how to deal with this new situation. Momo might have to use her intelligence and creativity to find a way to get Izuku's powers back or to help him adapt to a powerless life. Another plot twist could be that a villain kidnaps Momo on the wedding day, and Izuku has to go on a rescue mission, showing his heroic side even on his big day.
In many 'izuku healing quirk fanfic', the way his quirk interacts with other characters' quirks is fascinating. For example, if another character has a self - destructive quirk, Izuku's healing quirk could have a unique way of countering it or working in harmony with it. Also, the discovery of new aspects of his healing quirk during intense battles or crises can be a major plot point that drives the story forward.
One interesting plot twist could be that Izuku initially doesn't know about his father's true identity. He grows up believing he has no quirk and then discovers his father is All For One. Another twist could be that All For One has some hidden motives for fathering Izuku, like using him as a pawn in a bigger scheme against the heroes.
One interesting concept could be how the stretch quirk is used in combat. For example, the character with the stretch quirk might be able to reach far - off enemies or create barriers by stretching their body parts. Another concept could be the limitations of the stretch quirk. Maybe there are times when over - stretching causes pain or temporary loss of control. Also, the social implications within the BNHA universe. How do other characters perceive the one with the stretch quirk? Are they seen as useful in rescue operations or just a novelty in hero battles?