A fallen star in this fanfic could be a metaphor for a character's fall from innocence. In Harry Potter, think of how some characters like Draco Malfoy started out with a certain level of innocence but were influenced by their families and the dark side. In Fairy Tail, a character might start as a bright - eyed newbie but then face hardships that cause them to lose that initial spark. The fallen star could then be the focal point of their journey to regain what they've lost or to come to terms with their new self.
A 'Fallen Star' in a Harry Potter and Fairy Tail fanfic could be a very interesting concept. It might refer to a character who was once highly regarded but has fallen from grace. In the context of Harry Potter, it could be a wizard who has turned to the dark side, perhaps influenced by the Death Eaters' ideology. In Fairy Tail, it could be a mage who has lost their power or been exiled from the guild. The fanfic could explore their journey to redemption or further descent into darkness.
Natsu could be the main character. His impulsive and adventurous nature would make him immediately interested in the fallen star. He might see it as a new challenge or a source of great power that he could use to become even stronger. He would charge head - first into any situation related to the fallen star, dragging his friends along with him in the process.
One idea could be that the fallen star is actually a powerful wizard from a different dimension who has lost their powers during the fall. They end up in the Fairy Tail world and have to team up with the guild members to regain their powers and find a way back home. Another plot could involve the fallen star being a magical object that holds a great secret, and Fairy Tail members race against an evil guild to discover and protect it.
Maybe a fanfic where the Sorting Hat from Harry Potter is brought to Fairy Tail. The guild members could be sorted into Hogwarts houses based on their personalities. Natsu might be a Gryffindor because of his courage, while Lucy could be a Ravenclaw for her intelligence. This could lead to some interesting interactions and competitions within the guild as they explore the different aspects of the Hogwarts houses.
One possible plot could be that a character from Fairy Tail gets accidentally transported to the Harry Potter universe but is neglected by the magical community there. They then have to find their own way to get back while also discovering new magical abilities and making unexpected friends.
In fanfic, tattoos can have magical properties. A tattoo of a magical object, say the Elder Wand, might give the wearer some power related to the object. It could also be a form of protection. If a character has a tattoo of a powerful charm, it might protect them from certain dark magic. Moreover, tattoos can be used to tell a character's backstory. A character with a tattoo of a certain place in the wizarding world might have had an important experience there.
Maybe it could be due to a misfired spell in Hogwarts. Some student might accidentally cast a spell on Harry, and instead of the intended effect, it makes him grow a tail. It would be a really strange and comical situation for him.
Well, it could be a lot of things. It might be a star that has some sort of prophecy associated with it. In fanfiction, an author could create a story where the 'Second Star on the Right' is a key element in a battle between good and evil. For instance, when the star shines brightest, it could be the time when a hero must face a great evil. Or perhaps it's a star that gives special powers to those who can reach it in a magical journey, and this becomes the central plot of the fanfiction story.
There could be many amateur fanfic writers out there. It might be someone who really loves the Harry Potter series and wanted to create a really unique and funny story. So it could be just an unknown fan who wanted to put their own spin on the wizarding world.
Harry's family could be powerful allies. His father, for instance, might be a skilled fighter and could join in battles against the dark guilds in Fairy Tail. His mother could use her magic to heal the wounded wizards in the guild. And Harry himself could be a source of inspiration for the Fairy Tail members with his experiences of facing great evil.