Delphini LeStrange-Riddle

Delphini is the daughter of Lord Voldemort and Bellatrix LeStrange. She was born sometime in 1998 prior to the Battle of Hogwarts. 
== Early Life ==
Delphini was born at the Malfoy Manor in the mid to late 1990s in secret and was orphaned on May 2nd 1998, as both her parents were killed in the Battle of Hogwarts. Bellatrix LeStrange's husband, Rudolphus LeStrange survived the battle but was sent to Azkaban prison for his crimes. 
The young girl was left orphan just as her father had been. Delphi was raised by Euphemia Rowle who Delphini claims only took her in for the money. The woman kept a pet Augurey and claimed that it cried because it knew Delphini would come to meet a "sticky end." 
Delphini did not attend Hogwarts School of Witchcraft and Wizardry. She apparently had little to no contact with other children, claiming that she didn't have a best friend at the age of 14, and that she even invented an imaginary one when she was younger.
At some point, her step-father Rudolphus LeStrange was either released from Azkaban or escaped a second time. He told Delphini about her true heritage and the prophecy he believed she was meant to fulfill. 
== Tricking Those Around Her ==
Delphini eventually found Amos Diggory, the father of Cedric Diggory who died in the Tri-Wizard Tournament, and placed him under a powerful Confundus Charm in order to pass as his niece so she could get a plan in motion to bring her father, Lord Voldemort back. 
She met the son of Harry Potter, Albus Potter, when Amos Diggory had visited the Potters' home after Amos found out that a time turner still existed. He wanted it to be used to bring back his son. Albus was listening to a conversation between Diggory and Harry. Harry tried explaining to Amos that using a time turner would not work, as one detail changed could destroy the present. 
When Albus was on the train back to Hogwarts, he talked about finding the Time-turner and bringing Cedric back to his best friend, Scorpius Malfoy. Albus no longer wanted to live in the shadow of his father and believed he could help Mr. Diggory. The two boys ditched the Hogwarts express and after a close call with the trolley witch, they made it out. Albus and Scorpius traveled to St. Oswald's Home for Old Wizards and Witches where Delphini was pretending to be Amos' caretaker. They told Amos they'd help bring back Cedric and Amos told Delphini to go with them. 
The trio traveled to the Ministry of Magic and stole the Time-Turner from Minister Hermione Granger's office. From there they went to the Forbidden Forest and Albus and Scorpius traveled back in time. They created two alternate realities and had to fix them each time before realizing Delphini was their enemy. 
Albus then sent an owl to Delphi. She arrived to Hogwarts just in time to see how he planned to try to destroy the Time-Turner. Albus wanted to apologise to her that they would not be able to go back in time to save Cedric. He and Scorpius explained that in the new reality they had created, Cedric’s Triwizard humiliation had turned him into an angry, bitter young man who became a Death Eater and eventually murdered Neville Longbottom before he could destroy Nagini, helping to usher in the era of the Dark Lord. Delphi said that Cedric would have understood, suggesting they should destroy the Time-Turner together, and explain to her uncle why Cedric would not be saved.
After Albus handed her the Time-Turner, both boys noticed a black tattoo of a bird on her back. Delphi said it was an Augurey, which reminded her of her childhood as an orphan when she was raised by the Rowle family. The boys realised she was an enemy based on Scorpius recalling references to 'the Augurey' in the timeline where Voldemort won, but Delphi pulled out a wand and bound them together.
Delphi planned to travel back in time to ensure Cedric's survival in the third task of the Tournament (Unable to go back to the first two as the boys' actions made those events too temporally unstable). Albus refused, but she threatened to kill Scorpius. Craig Bowker Jr, another Hogwarts student, rushed up to say that the whole school was looking for them, then was killed by Delphi immediately, similar to the nature of her parents who didn't hesitate to kill.
Delphi took Albus and Scorpius back in time with her, but they refused to cooperate. As Delphi prepared to kill Scorpius, she was struck from behind by an unsuspecting Cedric Diggory, who thought the scene was simply part of the Triwizard task. He freed the boys before returning to the challenge.
Then Delphi staggered to her feet and picked up the Time-Turner, but Albus and Scorpius managed to grab the device. They raced through time once again, but once they arrived, Delphi destroyed the Time-Turner and flew away.
Albus and Scorpius discovered that they had been transported to 30 October 1981 — the day before Harry Potter’s parents were murdered by Voldemort. The boys realised that Delphi intended to stop Voldemort from trying to kill Harry, and thus triggering his own destruction when his Killing Curse rebounded on him due to Lily Potter's loving sacrifice.
Meanwhile, the boys' parents were looking for them. Ron Weasley told Harry he had seen Albus with an older girl the night before. Harry thought he must mean Delphi Diggory, Amos’s niece. They went to see Amos, who told them that he never had a niece. The Confundus Charm that Delphi had cast on him had waned.
The adults raced to Delphi’s room and found there writings revealing Delphi to be Tom Riddle's daughter and that she believed she could restore him to power following the words of a prophecy.
=== Found Out by the Golden Trio+Friends ===
Albus and Scorpius were able to send a message to their parents by leaving a message on Harry's old baby blanket, treated with a potion that would only become visible when it interacted with another potion Albus had spilled on the blanket shortly before this final trip back through time. Now aware of where their children were, Harry, Ginny, Draco, Ron, and Hermione headed back to Godric’s Hollow in 1981 using another Time-Turner in order to help the boys. They found Albus and Scorpius, and all of them hid in a church, from which they could look out for Delphi without being seen.
Harry volunteered to transfigure himself into Voldemort and lead Delphi into a trap. The others planned to wait in the church behind the large wooden doors until Harry was able to lure her inside.
Delphi finally appeared and Harry (disguised as Voldemort) pretended not to know who she was. She explained that she was the child of Tom Riddle and Bellatrix Lestrange.
He told her that together they could become an unstoppable force, but, by that time, the transfiguration had begun to fade. She saw that she was actually speaking to Harry, claiming she had studied him and knew him better than her father did. She locked the doors to prevent the others jumping out to help. Without a wand, Harry was forced to hide beneath a church pew while she attacked him. When Delphi was about to kill him, Albus popped up through a hatch in the floor, throwing a wand to his father. Together, they were able to overpower Delphi.
Delphi begged them to kill her or wipe her mind clean. She claimed that she had only wanted to meet her father and be with him. Albus wanted to kill her to avenge Craig, but Harry stopped him. In a moment of empathy for her, Harry told her that she must learn to live with the fact that she will always be an orphan, as he has.
Delphi was then imprisoned in Azkaban for her crimes.
== Post-Azkaban ==
Raven Potter broke Delphini out of Azkaban with the intent of reuniting her with her father. Raven believed her brother was insensitive about Delphini's past and wanted to offer Delphini a second chance at life, something Harry would've never given her.
When Delphini discovered that Lord Voldemort was alive, thanks to the war with the angels, this caused discontent in the Wizard Club. Harry Potter and Jason Daniels both confronted Raven about her actions, believing that Raven had defected from the Wizarding World itself and perhaps even wanted to destroy it. Raven was rejected by The Wizard Club who now accepted Jason Daniels as their leader, and went on to start the Dark Wizard Club with those who agreed with Raven's stance including Delphini. 
Delphini went on to help Raven conquer the Ministry of Magic and the Magical Congress of the United States of America, and has a hand in teaching Dark Arts at Hogwarts School of Witchcraft and Wizardry. She helped Raven fight a great many threats to the Wizarding World and now resides with The Dark Wizard Club at the Malfoy Manor.