Voldemort unwittingly makes himself a Horcrux for Harry, although it might not be called that, by taking his blood earlier. In taking Harry's blood to regenerate himself, Voldemort ensures that Harry will not die if Voldemort kills him. The blood ties Harry to Voldemort's life, therefore Harry will live.
No, Harry was not immortal. As the other answers said, the Horcrux protected Voldemort, not Harry.
But he didn't die, and the reason's rather simple: when Voldemort cast the killing curse, it only killed the piece of his soul within Harry, not Harry himself. Harry then saw Dumbledore in a version of King's Cross station, something that Dumbledore said was happening in his head.
Of all the Harry Potter characters killed off in The Deathly Hallows, only Harry himself successfully returned to life after being hit with the Harry Potter killing curse (for a second time). The main reason for this is fairly obvious: Harry was the master of all three of the titular Deathly Hallows.
Voldemort was scared it had gone wrong and was nervous to check. It was only when Narcissa checked that his arrogance returned. Only then he made up lies about Harry running despite all DE and Hagrid knowing that wasn't true.
Draco Malfoy's mother Narcissa was cold, cunning and devoted to the Dark Lord. But she was also a mother, which meant she was willing to risk everything to make sure her son was safe. When Harry survived Voldemort's Killing Curse for the second time, Narcissa pretended he was dead so she could get to Draco.
Voldemort intentionally made six Horcruxes, but when he used Avada Kedavra on Harry, he unintentionally created a seventh Horcrux. Instead of dying, Lily's love for Harry created a counter 'curse' known as Sacrificial Protection and saved Harry.
The Rowling Library on Twitter: "Without Hermione, Harry would have died in book one.
Though Harry encountered many opportunities that deemed Avada Kedavra necessary, it remains as one of the Unforgivable Curses Harry Potter never cast. For one, he viewed the spell as an immoral practice commonly used by users of the Dark Arts.
Who is immune to Avada Kedavra? Phoenixes were semi-protected from the Killing Curse, due to them being immortal. In 1996, Fawkes swallowed one intended for Albus Dumbledore, causing him to burst into flame and die instantly. However, he then was reborn from his ashes.
Her sacrifice gave Harry the power of love, a protection spell sealed with the blood spilled by her death.
Gaunt's ring
After retrieving the ring Albus Dumbledore himself fell victim to a curse that, even when contained, would likely have killed him within the year. Once rendered defunct as a Horcrux, the stone was placed inside a Golden Snitch and left to Harry Potter in Dumbledore's will.
The Stone's power really just reminded the dude and his ghost love of what they were missing, rather than making them feel like they were together again. Dumbledore left Harry the Resurrection Stone (disguised in a Snitch) in his will, and Harry uses it just before he goes to battle Voldemort.
He was sure there were Horcruxes after laying a eye on the diary (or at least started to think Voldemort might have them). What we, however, do know is that by the time book 4 came along, Dumbledore knew that Voldemort had Horcruxes and he also knew Harry would have had to die - expect this had changed.
Voldemort wasn't aware of Harry being a pseudo-horcrux because he didn't plan it, and Harry didn't know either until Voldemort “killed” him, but he actually killed the piece of soul kept in him.
Nothing about Harry being a Horcrux, or Nagini being a Horcrux, or Voldemort having Horcruxes at all. Snape did not know and Dumbledore tried to phrase everything the way it would not specify the kind of magic.
The darkest of the Dark Arts, Harry Potter unforgivable curses are the Cruciatus Curse, the Imperius Curse, and the Killing Curse. Although the curses are highly illegal, Harry using Unforgivable Curses happened, but he uses them once he was thrust into the Second Wizarding War.
The three Unforgivable Curses in Harry Potter are Crucio, Imperio, and Avada Kedavra, and all three are available to Hogwarts Legacy players. Crucio subjects the victim to extreme torture, while Imperio puts them under the control of the spellcaster.
Avada Kedavra
Topping the list for the most powerful spells in the Harry Potter universe is no other than Avada Kedavra, Voldemort's favorite to instill his will and fear onto others. The spell itself is a play on Abra Kadabra and is easy to cast by just about anyone in the Wizarding World.
While Dumbledore was a depressing death for Harry Potter to face as his only real father figure, the death of Sirius Black hit him the hardest. When Sirius first showed up in the pages of Harry Potter and the Prison of Azkaban, Harry thought the man was responsible for the death of his parents and wanted him dead.
The Tales of Beedle the Bard first appeared as a fictional book in J. K. Rowling's 2007 Harry Potter and the Deathly Hallows, the seventh and final novel of the Harry Potter series. The book is bequeathed to Hermione Granger by Albus Dumbledore, former headmaster of Hogwarts School of Witchcraft and Wizardry.
Voldemort Aside, Harry Potter's Highest Kill Count Belongs to a Surprising Hero. Harry Potter's Lord Voldemort undoubtedly has the highest body count in the series, but one unlikely wizard could offer strong competition.
A doe. And in his final battle with Lord Voldemort, Harry explained the significance of this to his adversary, and to us: 'Snape's Patronus was a doe,' said Harry, 'the same as my mother's, because he loved her for nearly all of his life, from the time when they were children'.
The death eaters now quite effectively used the cruciatus and imperius curse as you might have seen, but why only rarely the avada kedavra curse? It's because it requires strength, powerful magical ability, to be able to use a curse of that magnitude and power, and that too repeatedly during a duel.