A possible plot might involve the 'father of vampires' being a key figure in a prophecy that Harry discovers. The vampire has the power to either save or destroy the wizarding world. It turns out that he has his own motives and desires that are not entirely clear at first. He may be trying to gain control over the vampire population in the wizarding world, which has been growing out of control. Harry and his friends have to figure out whether to trust him or not as they try to prevent a war between wizards and vampires that could be catastrophic for both worlds. They also learn about the true origins of vampires in the Harry Potter universe through their interactions with the 'father of vampires'.
Yes, there are likely fanfictions out there with the concept of the 'father of vampires' in the Harry Potter universe. Fanfiction writers often come up with creative and unique ideas that blend different elements of the HP world. You can try searching on fanfiction websites like FanFiction.net or Archive of Our Own to find such stories.
One possible plot could be that Harry discovers he has a hidden connection to the vampire world and is actually the heir to the 'King of Vampires'. He then has to balance his life at Hogwarts with his newfound vampiric identity, facing challenges from both the wizarding world that may fear him and the vampire world that may have its own power struggles.
Maybe the fanfiction could focus on Harry as a father dealing with the pressure of his kids being in different Hogwarts houses. For example, if one of his kids was sorted into Slytherin, he would have to overcome his own prejudices from his school days and support his child wholeheartedly. He could also teach them about the importance of unity between the houses.
Well, it could be that Harry Potter, being adopted by the vampires led by Lord Vampires, has to adapt to their nocturnal lifestyle. He might learn special vampire skills like super speed or mind - reading among them. And there could be a struggle as he tries to balance his wizarding world values with the new vampire - centric ones.
In this fanfiction, perhaps there's a spell or some dark magic at play that has misled Harry all his life about his father. It could lead to a whole new adventure as he tries to find out the truth. He might have to face some old enemies of his real father or make new allies in the process of uncovering his true heritage.
One possible plot could involve Harry Potter's father, James Potter, having some sort of encounter with a Murkrow (which is a Pokémon) in a fanfiction world where the boundaries between the Potterverse and Pokémon are blurred. Maybe the Murkrow has some special power or knowledge that James needs. As for Dokuro, if it's a character from a different series, it could be that this character is brought into the story as an ally or an enemy. For example, Dokuro could be a magical being from a different realm who tries to either help James achieve a goal or stop him from doing something dangerous.
Maybe in the fanfiction, there has been some sort of misunderstanding or false accusation that made people initially think Harry was the father. Then the story could be about him proving his innocence and finding out who the real father is.
Dumbledore could be a main character. He might be aware of Harry's situation and be secretly guiding him from afar, trying to make sure Harry doesn't lose his wizarding identity. Also, a powerful vampire under Lord Vampires, like a vampire princess or prince, could be a main character. They could befriend Harry and teach him about vampire culture.
In some fanfictions, it could be Sirius Black. Some fans like to imagine that Sirius had a deeper connection to James Potter's family than just being best friends. They might create a scenario where there was some sort of magic or prophecy involved that made Sirius more than just Harry's godfather, but his actual father in this alternate story line.
Maybe Ron Weasley. Imagine a fanfiction where Ron, after getting married, has triplets. Given his humorous and sometimes clumsy nature, it would be really fun to see how he and his wife deal with three little ones. He could pass on his love for food and his loyalty to his children in a really endearing way.