Well, in these fanfictions, a frequent theme is the discovery of the past. Harry, as Merlin reincarnated, gradually uncovers memories or knowledge from Merlin's time. Also, the theme of redemption can be present. Maybe Merlin had some unfinished business in his past life, and Harry, as his reincarnation, has the chance to make things right. Additionally, the theme of mentorship often appears. Harry might be guided by the spirit or memories of Merlin, which helps him grow as a wizard.
A prevalent theme is the idea of fate. If Harry is Merlin's reincarnation, it implies that there is a greater plan or fate at work. He may be destined to save the wizarding world in a way that was pre - ordained. Also, the theme of power is often explored. How does Harry handle the increased power and knowledge that comes with being Merlin reborn? Will it corrupt him or will he use it for good? There are also themes related to the connection between the Arthurian legend and the wizarding world, like how the old tales might be intertwined with the current events in Harry's world.
One common theme is the transfer of power. Since Merlin is a very powerful wizard, when he reincarnates as Harry Potter, there's often a focus on how Harry now has access to that power. Another theme is the connection to the past. Harry might start to have visions or memories related to Merlin's time. And of course, there's the theme of destiny. Harry's original destiny in the Harry Potter series gets intertwined with whatever new path Merlin's reincarnation sets for him.
One common theme is the power struggle. Since Merlin was such a powerful wizard in legend, his reincarnation often brings a new power dynamic to the Harry Potter world. Another theme is the discovery of self. As the reincarnated Merlin, the character has to figure out who they are and what their purpose is in this new world.
Love and friendship are also common themes. In many Merlin reincarnation fanfictions, he forms new relationships. These relationships can be romantic or platonic. For example, he might meet someone who reminds him of an old friend from his past life. And of course, the theme of redemption can also be present. If he made mistakes in his past life, he might get a chance to make up for them in his new reincarnation.
A common theme is the power of magic. Since both Harry and Merlin are associated with magic, fanfictions often explore different aspects of magic, like how they can combine their powers or learn from each other's magical abilities. Another theme is friendship. They come from different time periods but still form a strong bond in many stories.
A prevalent theme is the exploration of magic itself. How the magic in the Harry Potter universe and that in the Merlin universe are related or different. Also, destiny plays a role. Fanfictions often explore how their destinies are intertwined, whether it was meant to be that they meet and change the course of events in both their worlds.
One common theme is the clash of magical cultures. Since Harry comes from Hogwarts and Merlin from Camelot, their different ways of using magic often create interesting situations. Another theme is friendship. The stories usually show how Harry and Merlin form a strong bond despite their different backgrounds.
One common theme is power. Since Harry is the son of Merlin, there's often a focus on his unique and powerful magic. For example, he might have abilities that other wizards don't, like being able to control time in some fanfictions.
One of the main themes is the discovery of a shared destiny. In many 'Harry and Merlin Mates' fanfictions, they find out that they are meant to be together for a greater purpose, like saving the magical world. Also, the theme of mentorship exists. Merlin, being more experienced in magic, often mentors Harry, and this relationship dynamic is explored in different ways in these fanfictions.
One common plot device is the discovery of ancient artifacts or prophecies that link Harry to Merlin. For example, a magical amulet that was once Merlin's might be found and react only to Harry. Another is the appearance of a character who knew Merlin in the past and recognizes Harry as his reincarnation.