One possibility is that Harry learns his ancestors were involved in the fight against dark wizards in the past. They might have been part of an ancient order that fought against the predecessors of Voldemort. This knowledge could give Harry a greater sense of connection to the long - standing battle between good and evil in the wizarding world. It could also inspire him in his own fight against Voldemort and the Death Eaters.
He could discover that he has a long line of powerful wizards. Maybe some of his ancestors were great duelists or inventors in the wizarding world. For example, they might have created spells that are now lost or forgotten.
It's possible that his ancestors were related to some of the more mysterious families in the wizarding world, like the Lovegoods. Maybe they shared certain magical abilities or eccentricities. They could also be linked to the Blacks, which would mean he has a connection to that complex family tree full of dark and light wizards.
Well, he might learn some long - lost family magic. Maybe his ancestors would teach him spells that have been forgotten over the generations.
The story could start with Harry finding an old family heirloom that has a connection to his ancestors. This item acts as a portal or a key to access the knowledge and training of his ancestors. They could train him in the art of wandless magic, which was more prevalent in the past. This would give Harry an advantage as he could use magic even when his wand is lost or broken. Also, his ancestors might teach him about the history of the wizarding world from a different perspective, helping him understand the roots of the dark magic that Voldemort uses and how to counter it.
Well, it could be that Dumbledore, in some fanfic versions, figures it out first and then reveals it to Harry. Dumbledore is often portrayed as having a deep understanding of magic. He might have noticed some strange magical patterns or behaviors related to Harry that led him to suspect and then confirm that Harry was a Horcrux. And then he would tell Harry about it, which is how Harry comes to know.
He might learn about hidden magical talents in his family. For example, perhaps there were ancestors who could communicate with magical creatures in a unique way that was lost over time.
Maybe Harry Potter uses a magical device to learn advanced spells. For example, he discovers a time - turning quill that allows him to study ancient magic more efficiently.
In 'Harry Potter Learns Voodoo' fanfiction, perhaps Harry would learn voodoo from a mysterious character who has some connection to the wizarding world. He could then combine voodoo spells with his own Hogwarts - taught magic. For example, using a voodoo charm to enhance his invisibility cloak's power. This would open up a whole new set of adventures and challenges for him as he tries to master this new form of magic while still dealing with the regular threats in the wizarding world.
Another truth could be related to the wizarding world's history. Harry might learn that there are secrets about the founding of Hogwarts that have been kept from him. For example, he could discover that one of the founders had a connection to a powerful magical artifact that is now lost. This knowledge would change his perspective on the school he loves and his place in the wizarding world.
It could be Dumbledore. He always has a knack for providing Harry with useful tools. Maybe he found this device during one of his travels and thought it would be beneficial for Harry's growth as a wizard.
Maybe a wizard who has traveled to far - off lands where voodoo is practiced could teach Harry. This wizard could have seen the power of voodoo and thought it could be useful in the fight against the Dark Arts in the wizarding world of Harry Potter.