To recap the key event in question, in an effort to save Cedric's life, Scorpius and Albus go back in time and try to change the Triwizard tournament. Part of this involves humiliating him at the second task, using an engorgement charm on him so he blows up like a balloon in front of the whole school.
Due to his humiliation in the Triwizard Tournament, Cedric eventually becomes a Death Eater and kills Neville Longbottom. Due to Neville's death, the final Horcrux Nagini was never destroyed, and as a result Voldemort is never defeated, kills Harry and takes over the Wizarding World.
Harry managed to escape the graveyard with Cedric's body, returning him to his devastated parents (Amos openly sobbed and screamed later while Harry explained what happened). Amos thanked Harry for returning Cedric's body, and assured him that they did not blame Harry for his death.
They sought to save Cedric and created an alternate timeline where Cedric survived and became part of the Death Eaters, because of the humiliation they caused him when they tried to save his life. Cedric's original and heroic life and death was later restored.
He describes himself as the "spare" son, making an allusion to what Voldemort called Cedric before his murder. Albus's ultimate desire is to have a good relationship with his father; he knows that even a small thing like preventing Cedric's death could change Harry's view of him.
Albus ended up in Slytherin because he couldn't stop thinking about ending up in Slytherin, and so the Sorting Hat couldn't grasp anything other than his thoughts about being in Slytherin.
He has grown afraid of Harry's connection to Voldemort. Perhaps Voldemort, knowing Dumbledore's love for Harry, would possess Harry and provoke Dumbledore to kill him. So, Dumbledore attempted to avoid Harry throughout Book 5 for Harry's own good.
did Cedric--did he--m--m--mention me at all before he died?' This was the very last subject on earth Harry wanted to discuss, and least of all with Cho. 'Well--no--' he said quietly. 'There--there wasn't time for him to say anything.
The Heir of Hufflepuff was none other than Cedric Diggory, who was well on his way to fulfilling the prophecy of the Heir of Hufflepuff when he was tragically murdered by Peter Pettigrew.
Narcissa's greatest moment, however, was when she chose to betray Voldemort in Harry Potter and the Deathly Hallows. Not knowing whether Draco was alive or dead, Narcissa chose to lie to the Dark Lord rather than risk losing her son.
All Potter fans know the story: Harry glimpses Snape's “Worst Memory” in fifth year and discovers that his father was not the great guy that any orphaned child would prefer to envision. His dad was a horrible bully who tormented fellow classmates and had a towering ego to match.
Xenophilius Lovegood betrays Harry in Harry Potter and the Deathly Hallows. The Death Eaters have Xenophilius' daughter, Luna.
It is interesting also to note that Harry does not actually kill Pettigrew, but that Voldemort's gift kills him despite Harry's efforts to save him. Pettigrew's death is a reaction to his own attempt to kill, or at least, disable Harry, coupled with Voldemort's distrust of his own lieutenant.
Voldemort created several of them but in the end he was still mortal and died that way. Lord Voldemort petrified Neville Longbottom, put The Sorting Hat on his head and sets it on fire. Neville is horribly tortured by being burned to death in a last moment of bravery and defiance.
Cho Chang is a Ravenclaw student one year above Harry, and is the Seeker for the Ravenclaw Quidditch team. She is Harry's first love interest, is described as being "very pretty" with long dark hair and is frequently accompanied by a group of giggling girls.
Dumbledore : SPOILER: Today we acknowledge a really terrible loss. Cedric Diggory was, as you all know, exceptionally hard working, infinitely fair-minded, and most importantly, a fierce, fierce friend. Therefore, I feel you have the right to know exactly how he died.
Harry goes along the passageway for a long while until he finally emerges in Honeydukes sweetshop. He finds Ron and Hermione and tell them about the map. Hermione wishes Harry would turn it in, concerned that Black might know about the secret entrances on it.
Eldritch is Gedric Diggory's grandfather, the great-grandfather of Amos and Benedict and great-grandfather of Cedric Diggory.
Moaning Myrtle
Born in the late 1920s to Muggle parents, Myrtle Warren started her Hogwarts life in the early 1940s, where she was sorted into Ravenclaw. She had no friends, and was bullied relentlessly because of her glasses and acne. But she would soon have all of eternity to get her own back.
Even J.K. Rowling says that Hufflepuff is her favorite House. It's produced the fewest Dark wizards of all four Houses. Hufflepuffs are down-to-earth. Literally, their House colors represent wheat and dirt, symbolizing their humility (rather than the precious metal secondary colors of the other Houses).
He is cunning
Slytherins are a cunning lot, and there are all kinds of examples of Albus Potter using his wiles to come up with schemes and plans worthy of any member of Salazar's house throughout Harry Potter and the Cursed Child.
Albus Potter was placed in Slytherin House because he wanted to be with Scorpius Malfoy, his first friend in the Hogwarts Express. Also, the Sorting Hat saw that he would do good in Slytherin, like it did to Harry, but the change is that he wanted to be in Slytherin, so he was put in Slytherin, unlike his father.
The big “secret” about the Dumbeldore family that the title promises is actually an explanation of the last film's cliffhanger. Albus confirms to Creedence early on in the film that he is in fact a Dumbledore, quashing any rumor that Grindelwald had lied to the young boy in order to sway him to his movement.