He may use a powerful spell combination. For example, he could start with a Confundus Charm to confuse the Horntail and then follow up with a blasting spell to deal a significant amount of damage.
One consequence could be that he becomes a hero among the wizarding community. People start to look at him with even more admiration and respect. His reputation as a powerful wizard grows even stronger.
In the 'harry kills the horntail fanfiction', Harry likely overcomes the Horntail dragon through his courage and magical skills. Maybe he uses a combination of spells like the Stunning Spell and the Fire - Making Charm to defeat it. He might also have some strategic maneuvers, such as using his broomstick to dodge the Horntail's attacks and find its weak points.
Often, in these fanfictions, Harry's knowledge of the Horntail's weaknesses plays a crucial role. He might have spent time researching about the Horntail in the library at Hogwarts. When it comes to the actual fight, he uses this knowledge. He aims for the Horntail's soft underbelly or its eyes, areas that are more vulnerable, and with a well - aimed spell or a thrust of a weapon, he kills the Horntail.
Often, it's portrayed as extremely menacing. Its size and strength are emphasized, with its huge wings and long tail being described in great detail to create a sense of awe and fear. For example, a fanfic might describe the ground shaking as it lands.
The Hungarian Horntail is one of the most fearsome dragons in the Harry Potter series. In fanfiction, it often takes on even more complex and interesting roles. Writers might explore its backstory, like how it came to be in the Forbidden Forest or what its relationship with other magical creatures is. It can be a great antagonist, with its powerful fire - breathing and sharp horns, adding a lot of danger and excitement to the story.
One idea could be to write about a young wizard's first encounter with the Harry Hungarian Horntail. Maybe he's a new dragon keeper at Hogwarts and has to learn how to handle this very dangerous dragon. It could be full of action as he tries to avoid its fiery breath.
In some fanfictions, the Horntail and Harry might have a telepathic connection. This allows Harry to understand the dragon's thoughts and motives, and they work together to uncover secrets in the wizarding world. For example, they might find a hidden chamber that holds a powerful magic item that could change the course of the war against Voldemort.
I'm not sure about a specific 'Harry has a Hungarian Horntail' fanfiction. But you could search on Archive of Our Own. There are tons of Harry Potter fanfics there, and you might find one with this unique concept.
You can start by creating a vivid setting. Maybe the story takes place in a hidden valley near Hogwarts where the Harry Hungarian Horntail has made its lair. Then, introduce a conflict. It could be that the dragon's lair is in the path of a new magical construction project at Hogwarts, and the school has to deal with it without harming the dragon.