As The Boy Who Lived celebrates his 42nd birthday in the wizarding world, it is important to that he was once a horcrux, and he didn't even know. Harry Potter told the tale of Lord Voldemort and the teenager who brought him down, which he could do because he figured out the secret that made Voldemort almost immortal — horcruxes.
The dark objects are shrouded in mystery both in-universe as well as in the fandom, and the reality of horcruxes is extremely chilling. From different types of horcruxes, to the malicious deeds one has to perform to create them, these facts about the dark items will leave fans even more frightened than usual.
There Were Many Unknown Horcruxes In The Wizarding World
By virtue of being such dark and devastating magic, horcruxes were not spoken about openly in the wizarding world. The worst thing that Horace Slughorn did was to give Tom Riddle the answers he needed to create his own horcruxes.
This meant that besides Voldemort, there were also other dark wizards who had made horcruxes of their souls but nobody knew about them. The wizarding world was vast, and there were other horcruxes that existed in it that people were unaware of. It's chilling to think about how many wizards had split their souls by committing grave crimes.
Quirrell Was A Temporary Horcrux
The subject of splitting the soul was taboo, so information about it was limited, but Voldemort's character was an awful one, and his experimentations proved that there were different types of horcruxes that could be formed.
Poor Professor Quirrell was living proof that once the soul could be pushed to the limit, then it could be transferred temporarily into another being. Quirrell was a temporary horcrux for a fragment of Voldemort's soul, which perhaps means that Voldemort had fragmented his soul into way more parts than seven.
The Exact Way To Create A Horcrux Is Still Mysterious, But It Is Heinous
The horcruxes themselves were evil, but the process to create them was even more gruesome. J.K. Rowling has mentioned that she knows the exact method of creating the dark objects, but she has not divulged the steps.
What is known is that a wizard would have to do unimaginable acts of wickedness (like trying to kill an infant), and do terrible things to a human being involving death which would shatter their soul completely and allow them to cast it into objects.
Harry Was An Automatic Horcrux
Just like temporary horcruxes, there was also an automatic horcrux — Harry Potter. The Boy Who Lived did so at a great price, which was to carry a piece of Voldemort's mangled soul within himself until he was 17 years old.
Harry was left with much more than a scar, and this was most likely because Voldemort had cut up his soul so many times, that it was extremely unstable. The terrible act of casting a killing curse on a helpless baby was enough to further destabilize and tear up Voldemort's spirit, which attached itself to the nearest living being.
Creating A Living Horcrux Alters The Being
Binding the soul to an inanimate object was difficult enough, and required complex curses to keep it bound, but choosing the right object to make into a horcrux also played a part. If a living thing was made into a horcrux, the wizard's soul would contaminate the being completely or partially.
Much like how the locket and diary adversely harmed the people wearing or using them, the living thing that became a horcrux gained abilities (Harry could speak Parseltongue and was connected to the Dark Lord) and behaved differently after being turned. It's hard to imagine how much Harry's soul had to fight Voldemort's to stay good, and how badly Nagini was affected by the process.
Ripping The Soul Condemned It In The Afterlife
Ripping up a soul even once, let alone seven to eight times, went against nature. The soul was always supposed to stay intact and never be broken into pieces. Therefore, a ripped up soul would not get peace in the afterlife, and be stuck in limbo.
When Harry met Dumbledore at King's Cross Station, both of them saw a mangled-looking corpse the size of an infant curled up under a bench. J.K. Rowling confirmed that it was Voldemort's soul suffering for the dark wizard's crimes in the afterlife.
Voldemort Didn't Know About The Stone In The Gaunt Ring
Voldemort's biggest folly was choosing easily recognizable, iconic objects that held great meaning in the wizarding world. His pride did not allow him to place his soul in ordinary objects, but he had no idea what the value of the Gaunt ring and its stone was.
Voldemort only wanted the Elder Wand, but he unknowingly had the second Hallow, the Resurrection Stone, in his palm which he made into a horcrux. He did not know the great powers of the stone and only treated it like a vessel. It's hard to imagine what he would have done had he known the true value of the Gaunt ring's stone.
Each Horcrux Had Its Unique Negative Effects And Abilities
Apart from just the piece of soul, each horcrux was bound by curses and charms of various kinds which made them do different, horrific things. Tom's diary could speak to people and drain them of their life force to make Voldemort come to life, and Slytherin's locket could make the wearer extremely negative and do things that they wouldn't do necessarily.
Similarly, Marvolo Gaunt's ring had a curse in it that would instantly kill the person wearing it, which Dumbledore contained in one hand. It is likely the diadem and cup also would have some adverse effects on the people who came in touch with it.
Voldemort Would Have Survived If He Had Picked Ordinary Objects
A widely discussed Potter theory is that if Voldemort had placed his soul in everyday objects with no real meaning attached to them, he would have been invincible, which makes fans shudder. Famous objects are easier to pinpoint and track, as opposed to ordinary things that held no meaning.
It would have been impossible to even know what the objects were, let alone track them down. If he had not let his pride dictate his choices, Voldemort would have won the Battle of Hogwarts.
The Diadem Could Have Made Malfoy Feel Worse
Draco Malfoy had a tough sixth year, forced into helping Death Eaters to save his family, and stressing about how to bring them into Hogwarts as a mere sixteen-year-old. He spent large amounts of time in the Room of Requirement, so it's entirely possible that his demeanor changed the most because of the diadem being in close proximity to him.
Malfoy was emotionally damaged and extremely anguished every time he spent in the enchanted classroom, so the horcrux's effect was a lot more potent than anyone expected it to be.
