One possible plot twist could be that Merlin is carrying a child with magical powers far beyond what anyone has seen. This could lead to a race among the dark forces to either control or destroy the unborn child, while Merlin's friends strive to protect him and the baby.
A really interesting plot twist could be that the father of Merlin's child is actually a long - lost relative of Arthur. This would create a complex web of relationships and loyalties. It could also lead to a situation where Merlin's pregnancy becomes a key factor in uniting different factions in the kingdom, who would otherwise be at odds.
Maybe Merlin's pregnancy is a result of some ancient magic gone awry. In the fanfiction, it could be revealed that a spell backfired and Merlin became pregnant. This would cause a great deal of confusion and moral dilemmas within the Camelot court, as they try to come to terms with this strange situation.
One possible plot twist could be that Abby tries to hide her pregnancy from her colleagues at NCIS for fear of how it might affect her work. Maybe she's worried about being sidelined from important cases. Another could be that the father of the baby is someone unexpected within the NCIS world, like a character who has had an on - again, off - again relationship with Abby. And perhaps there's a mystery surrounding the pregnancy itself, like some sort of threat to the unborn baby that Abby has to deal with while keeping it all a secret.
Maybe Ichigo is secretly a girl because she's on a secret mission. In the fanfiction, she could be a spy or an undercover agent. Her guise as a boy has allowed her to infiltrate certain groups or places. When her true identity as a girl is discovered, it throws the whole mission into chaos, and she has to find a way to salvage it while dealing with the personal relationships that are affected.
Well, it could be that Stiles' secret vampire fanfiction is actually a premonition. He starts writing about a particular vampire who then shows up in real life. But this vampire is different from the typical ones in the stories. Instead of being evil, it's trying to find a way to co - exist with humans. Stiles then has to use his knowledge from the fanfiction to help this vampire, all while still keeping his vampire - loving side a secret from his friends.
Well, a plot twist might be that Freya discovers she's pregnant with a special kind of magic - not just normal magic but something that is a blend of different magical realms. This causes a stir in the magical community and they have to deal with the politics and jealousy that comes with it. Also, Merlin might have to hide this fact from Arthur for a while as he fears Arthur's reaction to such a strange magical occurrence.
One reason could be to protect the person he marries. If she's a commoner, for example, the noble society in Camelot might not accept their relationship. So, they keep it a secret. Another reason could be that the person he marries has some sort of power or identity that could put them in danger if it was known. For instance, if she was a sorceress, in Camelot where magic is feared, they'd have to marry secretly.
One possible plot twist could be that Hermione's pureblood status was hidden to protect her from a dark wizard or an old family feud. When the truth comes out, she has to face unexpected enemies.
Well, it could be Arthur in a more creative and alternative fanfiction. Their deep bond could be taken to a whole new level with this unexpected turn of events.
A plot twist might be that the baby has some sort of prophetic power even before it's born. This power could show visions to Morgana or Merlin about the future of Camelot. It could also be that the pregnancy is part of a grander magical plan set in motion centuries ago by an ancient sorcerer, and Merlin and Morgana are just pawns in this plan, not realizing the true significance of the pregnancy until later events unfold.
A possible plot twist could be that Merlin is not actually dead but has been trapped in a different dimension. Harry, as his son, has to find a way to free him. This would completely change the dynamic as they could then fight side by side against the forces of evil.
Well, one possible plot twist could be that Natsu has been hiding her true gender to be able to participate in male - dominated activities like a certain guild or sport. Another could be that she's in love with a male character, but is afraid to reveal her gender in case it changes how he feels. Or perhaps she has a special power that is related to her being a girl secretly, like a unique form of magic that only female dragonslayers can possess.