One frequent theme is the idea of identity. Harry, with his own identity as a wizard and the Boy Who Lived, has to grapple with Alucard's identity as a powerful vampire. Also, the theme of friendship or rivalry might be present. They could start as rivals due to their different natures but end up as friends who respect each other's abilities.
Alucard could fit as a powerful outsider. His vampiric abilities like super strength, speed, and the ability to turn into mist or a bat would be very different from normal wizard magic. He could be a sort of anti - hero, helping Harry when it suits his own goals. For example, if there was a dark wizard using blood magic in a way that threatened Alucard's existence too.
The character interactions are also very distinct. Harry is a young wizard who has grown up in a world of rules and order, while Alucard is a centuries - old, more or less amoral being. Their conversations and the way they view the world around them are really interesting to read. For instance, Alucard might see the Hogwarts houses as something completely different from what they are meant to be in the original series, and his views can challenge Harry's understanding of his own world.
Yes, there are some out there. However, it's a rather unique crossover concept. You can try searching on fanfiction - specific websites like Archive of Our Own or FanFiction.net. Just type in the title 'Harry Potter son of Alucard' in their search bars and you might find some interesting stories.
I'm not entirely sure it's a very common or 'legitimate' concept in the mainstream sense. Harry Potter and Alucard come from very different fictional universes with distinct rules and aesthetics. It might be a very niche idea within the fanfiction world created by a small number of fans who like to cross - over and blend these two elements in a creative way, but it's not something you'd typically see widely promoted or recognized.
Harry would likely be cautious at first. Alucard is a very different kind of being compared to the wizards he knows. Alucard, on the other hand, might be intrigued by Harry's magic. He could start by testing Harry's limits. But as they get to know each other, they might find common ground in their fight against evil. Harry could learn some of Alucard's more ruthless ways of dealing with enemies, while Alucard could understand the importance of friendship and loyalty from Harry and his friends.
I'm not sure about a specific one off the top of my head, but you can check fanfiction.net. There are often a lot of crossovers in that genre. You might search for tags like 'Harry Potter' and 'Alucard' to narrow down the results.
A common theme is the clash and eventual harmony of different power systems. Harry has his wizard magic from the Potterverse, and Alucard has his vampiric abilities. Their coming together often involves exploring how these powers interact. Another theme is the idea of redemption or transformation. Alucard, being a vampire, might be seen as a dark character, and through his relationship with Harry, he could experience a change.
There might be some. You could start by checking fanfiction websites like Archive of Our Own. Just search for 'alucard harry potter slash' and browse through the results. However, keep in mind that the quality can vary greatly.
Common themes often include the struggle between light and dark. Harry is typically associated with the light side in the Potterverse, while Alucard has a more ambiguous moral standing. There could also be themes of redemption as they influence each other. For example, Alucard might be influenced by Harry's sense of justice and Harry might come to understand the more complex nature of good and evil through Alucard. Additionally, friendship or a deeper relationship might be a theme as they learn to trust and rely on each other in the fan - created scenarios.