Content Warning: This article contains discussions of disturbing violence.
The Harry Potter fans had previously seen very little of. Grindelwald only played a minor part in Harry's story, but the spin-off movies have made it clear that the character's impact on Dumbledore was significant.
Still, Grindelwald doesn't seem to compare to Lord Voldemort regarding evil deeds. Yes, Dumbledore's old friend performed heinous acts of Dark magic, but he never wandered into the kinds of magic that Voldemort had been so fascinated with. This, of course, includes Horcruxes, the single biggest evil described in the Harry Potter series. The process of creating Horcrux is so disturbing that author J.K. Rowling stated that she would not share the details with her audiences. Of course, a subject so shrouded in mystery is difficult for fans to resist theorizing about, and Redditors have several dark and disturbing ideas about Horcruxes, from how they are really made to other ways that this unnatural magic affected Harry's story.
Harry Threw Off The Balance Of Seven
Because of the mysterious nature of Horcruxes, it has never been completely clear how Voldemort planned to use them to regain life if his central soul was ever killed. However, it's clear that things never went according to plan, and Redditors have some ideas why.
When he was in school, Tom Riddle noted that seven is the most magically significant number. This revealed to Dumbledore that Voldemort intended to make six Horcruxes, resulting in seven total fragments. However, one Reddit pointed out that Voldemort didn't "know about Harry" when he made Nagini into a Horcrux to achieve his seven. Of course, this resulted in eight instead, eliminating any magical protection Voldemort thought he had achieved.
A Split Soul Has No Afterlife
Voldemort feared death so much that he would have gone to any lengths to be immortal, even if it meant dooming his eternal soul. Redditor Madrb believes that after a soul has been split, there can be no afterlife for the destroyed pieces.
To this, they pointed out that "Harry gives Voldemort the opportunity to really 'feel remorse' for what he's done as a chance to save himself." Hermione explained that remorse was the only way to repair a split soul. It seems that Harry recognized that the fragmented piece of soul he saw in the King's Cross afterlife could not move on and that Voldemort was doomed to eternal death.
The Dark Wizard Must Sacrifice Their Body
When learning about Voldemort's past, he learned that if a dark wizard wants to create a Horcrux, they must first commit murder, splitting the soul. But Hermione explains that other unspeakable actions must take place to prepare the soul to be stored in another object.
Redditor Obversa has theorized that "the Horcrux's creator must physically "sacrifice" part of his/her body," explaining why Voldemort had become physically distorted by his experiments with Horcruxes. This is further enforced by the fact that Harry was accidentally made into a Horcrux when Voldemort's entire body was destroyed by his backfiring killing curse.
The Dark Wizard Must Consume Their Victim's Heart
Redditors had a great many disturbing Harry Potter fan theories about what other steps there are to make a Horcrux that Rowling was unwilling to share, but a popular one was posted by Redditor Starflashfairy. They believe Voldemort would have had to consume part of his victim's bodies, like their heart.
"There could easily be a sell to remove the victim's heart and eat it," this Redditor said, noting that this magic would have kept anyone noticing that the body had been defiled. Since Voldemort had been planning to use Harry's murder to create a Horcrux, it's possible that he had used Lily's body to prepare, which was how Harry became the vessel by mistake.
The Creature In "King's Cross" Was Voldemort's Destroyed Soul
After Harry's "death," he finds himself in a strange version of King's Cross station with Dumbledore and a repulsive creature in agony. Dumbledore tells Harry that this creature is beyond help, but he never thoroughly explains what it is.
This has spurred a discussion among fans, and Redditor Broadbeck7 shared a couple of their ideas. One was that the creature was all that was left of the "6/8 of Voldemort's soul that has already been destroyed." However, since Harry's soul was still alive in this state of limbo, it might not make sense that the destroyed portions of Voldemort would have ended up in the same place after the failed attempt to kill Harry.
The Creature In "King's Cross" Was Voldemort's Remaining Soul
If the shriveled creature in King's Cross wasn't the portions of Voldemort's soul that were destroyed, then Redditor his evil Horcruxes in Harry Potter.
"This is ed by the fact that when Voldemort attempts to kill Harry, he is also knocked out," this Redditor said, presuming that Voldemort's soul went into the "limbo" version of King's Cross along with Harry. Harry and Dumbledore appeared as whole people because their souls were intact, but Voldemort was reduced to almost nothing.
Dumbledore Hoped The Basilisk Would Kill Harry's Horcrux
In Chamber of Secrets, Harry and his friends were the only ones who figured out that Slytherin's monster was a snake, and Harry successfully faced off against the beast. This always seemed unlikely to fans, who struggled to believe that the clever Dumbledore was that ignorant of the Chamber.
However, Redditor OmegaSTC has a disturbing theory that might explain this. They shared that Dumbledore might have known all along what the monster was and had hoped that Harry's death "at the hands of the Basilisk" would destroy the Horcrux and Harry along with it. The heaster didn't know for sure that Harry was a Horcrux or even that Voldemort had split his soul until he saw the diary. However, Dumbledore was always good at guessing, and it has been made clear that he wasn't above sacrificing others for the greater good.
The Basilisk Was An Ancient Horcrux
Slytherin's monster, a Basilisk, can only be controlled by the heir of the Hogwarts founder himself. This meant that Harry, a Parselmouth, couldn't influence the beast since he did not share Slytherin's blood. However, Redditors like 08george have questioned why the heir can control the Basilisk to begin with.
Dumbledore mentions in Half-Blood Prince that Voldemort has unusual control of Nagini, leading him to believe that the snake was a Horcrux. "I wonder if perhaps Slytherin made the Basilisk a Horcrux," this Redditor said, pointing out that this would have given him and his heirs' control. There have also been theories that Slytherin's monster was created by Herpo the Foul, a Dark wizard whom many believe to be an ancestor of Slytherin. Herpo was the first to breed a Basilisk and, coincidentally (or maybe not), the first wizard to ever make a Horcrux. With all this information combined, it seems like the fan theory that the Basilisk is a Horcrux for one of these two Dark wizards makes sense.
Dumbledore Was A Temporary Horcrux
There has been a lot of confusion in regards to the King's Cross limbo that Harry found himself in after his failed murder. The fact that Voldemort's soul seemed to be there as well has made Redditors like Dragonspeeddraco believe that "this space might have something to do with the Horcruxes." But, if that is the case, what was Dumbledore doing there?
This Redditor theorized that this had something to do with the Horcrux ring. When Dumbledore put it on, a curse began to spread up his arm. It's possible that Voldemort had designed this curse to transfer his soul fragment from the ring into the victim, ensuring that he would rise again if anyone found it. This would mean that Dumbledore was a temporary Horcrux and that he knew that Snape needed to kill him before the curse fully took over so that Voldemort didn't get possession of his body — a truly terrifying thought.
