Exactly like Voldemort and Bellatrix Lestrange, Delphini was intensely sadistic, being easily able to cast the Cruciatus Curse with malicious intent and proving to be a dangerous opponent for even Harry Potter.
Delphini, nicknamed Delphi, is the titular main antagonist of Harry Potter and the Cursed Child. Although she initially introduces herself as the niece of Amos Diggory, Delphi is in fact, the child of Lord Voldemort and Bellatrix Lestrange and has only one goal, restoring her father.
She meets young Albus Potter and leads him to believe she is the niece of Amos Diggory, and cousin to the long-dead Cedric Diggory. But in the play's third act, Delphi reveals herself to be the daughter of Voldemort and Bellatrix Lestrange. Fans were shocked, to say the least.
Delphini (better known as Delphi) is the main antagonist of Harry Potter and the Cursed Child. She is the secret daughter of Bellatrix Lestrange and Lord Voldemort.
Much like Harry and Teddy Lupin, Delphini grows up as an orphan because both of her parents passed away during the Battle of Hogwarts. Unlike Teddy, however, she grows up without a loving support system. Rodolphus was sent to Azkaban, leaving Delphini in the care of Euphemia Rowle.
Following Lord Voldemort's defeat at the hands of her student Harry Potter and the deaths of Headmasters Albus Dumbledore and Severus Snape, McGonagall takes the position of Headmistress.
In the Cursed Child climax, Delphi disarms Harry. Harry has the Elder Wand in his possession. The Elder Wand passes allegiance by disarming (As in Draco Malfoy and Dumbledore).
The biggest revelation in Harry Potter and the Cursed Child was that Lord Voldemort had a daughter with Bellatrix Lestrange, who was named Delphini.
1 Lord Voldemort
Lord Voldemort is the scariest villain in Harry Potter, if only because he is the series' overreaching villain who successfully evades death more than once.
Delphini isn't canon and should be removed from the official Harry Potter Fandom Wiki.
By the end of The Crimes of Grindelwald, Nagini along with Newt Scamander, Tina, Jacob, Yusuf, Theseus, and Albus Dumbledore all became committed to defeating the Dark Wizard. Nonetheless, despite her initially benevolent nature, Nagini's blood curse eventually turned her into a snake permanently.
She found Amos Diggory (the person who really wants to save his son, Cedric) and placing him under a confundus charm. That's the time when she told him she's his niece and took his surname as a disguise.
Before her death, Bellatrix secretly gave birth to an illegitimate daughter named Delphini, whom she conceived with her beloved master, Lord Voldemort. Delphini was conceived sometime after the Battle of the Department of Mysteries in 1996 and before the Skirmish at Malfoy Manor in 1998.
In the Chamber itself, we see a large statue of a wizard, which Harry presumes is Salazar Slytherin. We also meet Tom Riddle, who is, as it turns out, the heir of Slytherin. Present only in spirit, he has all the same been controlling Ginny, and having her act as Slytherin's heir.
Delphi did not go to Hogwarts. She was kept at home with her adopted guardian (most likely home-schooled or self-taught). Given how adept she was at using magic later on in life, she's evidence that you don't need to go to Hogwarts to be a witch...
Delphi's whole existence was hidden from the Malfoys, even though she was born under their roof. She was seemingly smuggled out of the manor to be raised in secret by someone else. There was no way of Narcissa knowing.
Marge Dursley went a step further in tormenting Harry, making her the meanest of the lot.
1 Lord Voldemort
Considered the most powerful dark wizard of all time, Voldemort was obsessed with his own half-blood ancestry and his search for power and immortality.
Arguably more hated and more dangerous than Voldemort himself, there are many reasons why Dolores Umbridge is the most hated Harry Potter character. Dolores Umbridge was arguably the most evil character in the Harry Potter series, sometimes more so than Lord Voldemort, mainly Harry Potter and The Order of the Phoenix.
Bellatrix used a powerful "love potion" on Voldemort and they have sex while he is temporarily obsessed with her. She then uses obliviate on him while he sleeps (you know, he falls asleep after his post-sex cigarette) and tells everyone that the baby is her and her husband's.
Bellatrix's husband, as well as her maternal step-father, Rodolphus Lestrange, survived the battle, but was sent to Azkaban for his crimes. This left the young Delphi an orphan as her father had been. Euphemia Rowle took Delphi in and raised her, allegedly only because she was offered a substantial amount of gold.
She married Rodolphus Lestrange after leaving Hogwarts "because it was expected of her" to marry a pure-blood. However, Rowling stated in an interview that Bellatrix truly loved Voldemort.
Delphini is stronger than Harry Potter for several reasons. She is the daughter of Tom Riddle and Bellatrix Lestrange. Being the only child of Lord Voldemort, Delphi became the only known living heir of Salazar Slytherin after the demise of her father. ... DELPHI unleashes a bolt from her hand.
Therefore Harry would be considered only 'half' wizard, because of his mother's grandparents." Delphini's paternal grandfather, Tom Riddle Senior, was a muggle, so she is a half-blood.
MASS BREAKOUT FROM AZKABAN was a Daily Prophet article about the 1996 mass breakout from Azkaban, in which ten Death Eaters, including Bellatrix Lestrange, Antonin Dolohov, and Augustus Rookwood, were able to break out of their cells with the help of the Dementor guards, who had switched sides and were following Lord ...