One popular plot twist is Merlin's true origin. In some fanfictions, it is revealed that she has a much deeper connection to the world's magic or a certain ancient power than initially thought.
A common plot twist is related to Merlin's relationships. For instance, she might be secretly in love with a character, which completely changes the dynamics of her interactions with others in the story. Also, there could be a plot twist where Merlin betrays the Seven Deadly Sins for a greater good she has in mind, which throws the whole story into chaos.
In many Seven Deadly Sins fanfictions, a major plot twist involving Merlin is her power. Sometimes, it is discovered that she has been suppressing her true power all along. This could be due to a fear of its consequences or because she was waiting for the right moment. Another interesting plot twist is that Merlin is not actually on the side she appears to be on. Maybe she has been working for an unseen force all this time, and this revelation turns the story on its head, as the characters have to re - evaluate their trust in her and deal with the implications of her hidden agenda.
Another idea for the fanfiction could center around their relationship. Perhaps it explores how Merlin has always been intrigued by Escanor's duality - his meek self at night and his powerful self during the day. It could show how they gradually develop a deeper understanding and respect for each other, which might even turn into a romantic relationship over time.
One possible fanfiction could be about Meliodas and Merlin's adventures before they joined the Seven Deadly Sins. Maybe they were on a secret mission together, facing powerful enemies and having to rely on each other's unique abilities. Merlin's magic and Meliodas' strength would make for an interesting dynamic.
A simple plot could be that Meliodas and Merlin discover a hidden prophecy that only they can fulfill. They embark on a journey to find the key elements of the prophecy, facing various challenges along the way. Their relationship could grow stronger as they support each other through difficult battles and puzzles.
In such fanfictions, Merlin is often portrayed as a very powerful sorceress. She has an air of mystery around her. Her magic is usually depicted as extremely potent and she uses it to protect Arthur or further their shared goals. She might be shown as a manipulator at times, using her intelligence and magic to influence events in their favor.
A really cool plot twist could be that the magic in Fairy Tail is somehow connected to the sins in Seven Deadly Sins. So, when a Fairy Tail mage uses too much of a certain type of magic, it starts to manifest as one of the seven deadly sins. This could create a whole new set of challenges for the characters as they have to not only fight external enemies but also control their own inner 'sins' that are now linked to their magic.
One great fanfiction is 'The Sun and the Sorceress'. It beautifully explores the relationship between Escanor and Merlin. It delves into how their different powers and personalities interact. The story has some really heart - warming moments where Escanor's pride is shown in a new light in relation to his feelings for Merlin.
One idea could be a crossover where Naruto's world is invaded by the forces of the Seven Deadly Sins and Merlin from that universe has to team up with Naruto to stop them. Naruto's powerful jutsu and Merlin's magic could create some really interesting battle scenes.
One great fanfiction could be titled 'The Unseen Bond'. In this story, Merlin and Escanor's relationship might be explored in a world where they have to overcome a new threat to the Seven Deadly Sins. It could show how Merlin's magic and Escanor's strength combine in unique ways. Maybe there's a scene where Escanor in his 'The One' form is protecting Merlin while she casts a powerful spell that could save them all.
A plot could be that Escanor and Merlin are tasked with training a new generation of knights. They have different teaching styles, with Escanor focusing on physical and mental fortitude, and Merlin on magical abilities. This leads to some humorous and also some tense moments as they try to work together.
Merlin in the Seven Deadly Sins fanfiction often has a very complex character development. She starts off as a mysterious and powerful mage. Her actions are often driven by her own goals and the pursuit of knowledge. For example, she may manipulate situations to further her understanding of magic or the world around her.