Another plot twist could be that there are other hidden characters who knew about this relationship all along. Maybe All Might had an inkling but was sworn to secrecy. So when the truth comes out, it not only affects Deku but also those around him. In these fanfictions, there might also be a plot twist where Deku has to decide whether to accept or reject his father, AFO, given AFO's villainous nature.
One common plot twist is that Deku discovers the truth about his father in a moment of great crisis. For example, when he's facing off against AFO in a big battle, AFO reveals the truth to him, which completely shakes Deku's world view.
A common plot twist can also be related to Deku's powers. It could be revealed that his powers are somehow related to AFO in a more direct way than originally thought. For instance, his quirk might be a result of some experiment that AFO was involved in long ago. This changes how Deku views himself and his abilities, and adds a whole new layer of complexity to the story.
In most of such fanfictions, they might create evidence like hidden past connections. For example, AFO could be secretly involved in Izuku Midoriya's (Deku) family history. Maybe he had a relationship with Deku's mother long ago, which led to Deku's birth. But it's all fictional speculation within the fanfiction world.
A great plot twist might be related to their relationships. While in each other's bodies, they could accidentally say or do things that affect their relationships with other characters. For instance, Todoroki in Deku's body could unknowingly say something to Ochaco that makes her misunderstand Deku's feelings. Also, they could find it difficult to interact with their families in the other's body. Deku might not know how to handle Todoroki's father in Todoroki's body, leading to some tense situations.
A plot twist could be that they are being manipulated by a greater villain. They think they are in control of their actions as villains, but in reality, someone else is pulling the strings. This could lead to them realizing they are not true villains at heart and decide to turn against the real villain. Another possibility is that their villainous actions cause an unexpected reaction from the hero society. Instead of just fighting back, the heroes come up with a plan that forces Villain Deku and Villain Uraraka to re - evaluate their motives. For example, the heroes might start to offer amnesty to minor villains, which makes them wonder if they should continue on their villainous path.
In kidnapped deku fanfiction, the build - up to the kidnapping is common. There are often signs or threats before it actually happens. Then, Deku's state of being while kidnapped is important. Is he injured? How is he coping? And the role of his allies is crucial. They might have to overcome obstacles and their own fears to rescue him. For example, they could face other villains or traps on their way to save Deku.
One common plot twist is that Dumbledore knew all along about Harry being his grandson but kept it a secret to protect him. Another could be that there's a dark family secret that comes to light, like a curse on the family line that Harry has to break.
One common plot twist is that Hermione discovers her heritage at a crucial moment, like when she's about to be attacked by Death Eaters and suddenly some hidden power related to her being Voldemort's heir emerges. Another is that she has to struggle with the moral implications of being related to such an evil figure.
One common plot twist is that Snape was forced to hide his fatherhood due to some dark magic threat. Another could be that Harry's mother had some sort of pre - arranged deal with Snape that led to Harry's birth.
A typical plot twist is when Stiles initially hates Peter because of his reputation, but then as he discovers they are father - son, he has to re - evaluate his feelings. Also, there could be a plot twist where Peter's enemies target Stiles to get to him once the relationship is known. Or perhaps it's revealed that there was some kind of magic or prophecy involved in Stiles' birth that neither of them knew about, and this changes the whole dynamic of their relationship.
One common plot twist could be that Madara had his memories wiped and didn't know about Naruto being his son until some fateful encounter. Another might be that Naruto's mother was part of a secret mission involving Madara.
One common plot twist could be that the kidnapper is someone they least expect, like a close acquaintance with a hidden agenda. Another might be that Bughead discovers a secret about their captors during the kidnapping that changes the whole situation.