Gellert Grindelwald

Gellert Grindelwald is the most powerful and dangerous Dark wizard of all time after Lord Voldemort.
== Biography ==
Gellert Grindelwald attended the wizarding school Durmstrang, from which he was expelled at age sixteen for his dangerous and evil experiments that nearly resulted in the deaths of some of his fellow students. He left the symbol of the Deathly Hallows on one of the walls in Durmstrang before departing. After Durmstrang, he went to live with his great-aunt Bathilda Bagshot in Godric's Hollow in England, where he met the young Dumbledore who had been recently orphaned and left to put his plans to travel the world on hold to care for his younger siblings. In Deathly Hallows, it was revealed that Grindelwald had gone to Godric's Hollow to investigate the grave of the Peverell brothers (the original owners of the Hallows), but struck up a romantic relationship with Dumbledore. The two planned to establish a new world order, where wizards would rule over Muggles "for the greater good". The phrase later became Grindelwald's excuse for the atrocities he committed in his reign of terror. They also planned to work together in their quest for the Hallows. Later Rowling claimed at a Q&A session that she implied Dumbledore being once in love with Grindelwald, and thus he had 'lost his moral compass,' but she did not say whether those feelings were returned. Although it was later clarified in the Fantastic Beasts film series, that Grindelwald did reciprocate these feelings which is verbally confirmed when he shouts, "Who will love you now, Dumbledore? You're all alone!" at him. 
However, Aberforth Dumbledore, Albus's younger brother, argued against these plans, because he feared their grand ambitions would leave his and Albus's disabled, traumatised sister, Ariana, abandoned. Later the argument culminated in a three-way duel among Albus, Aberforth, and Grindelwald. Ariana was inadvertently killed by one of them. Grindelwald fled, fearing retribution and their relationship ended then and there. Grindelwald became master of one of the Deathly Hallows, the Elder Wand, by stealing it from the previous owner, the wand-maker Gregorovitch. Gaining the Elder Wand's immense power, he subsequently committed many terrible acts, terrorising Europe while avoiding Britain. It is revealed that Grindelwald's actions have caused many deaths that have greatly affected the students of Durmstrang, including Viktor Krum, whose grandfather was murdered by Grindelwald.
After Grindelwald's rise to power, Dumbledore delayed meeting him again for several years due to his fear of being confronted with his sister's death and the fact that he himself might have been the one who accidentally killed her. Both wizards were highly intelligent and skilled in battle, and when their battle eventually occurred, those who witnessed it later said that no other wizarding duel ever matched it. Grindelwald, who at the time possessed the supposedly unbeatable Elder Wand, lost to Dumbledore. Since Dumbledore won the duel over Grindelwald, the Elder Wand transferred its allegiance to Dumbledore. After Dumbledore triumphed over Grindelwald, the defeated dark wizard was imprisoned in the top-most cell of Nurmengard. He remained there, growing emaciated and toothless through the ravages of the prison, until Deathly Hallows when Voldemort arrives, seeking the Elder Wand. Grindelwald, showing no fear of Voldemort and welcoming death, tells him that he never owned the wand, and an enraged Voldemort kills him. In the chapter "King's Cross", Harry suggests to Dumbledore that, by lying to Voldemort to prevent him from breaking into Dumbledore's tomb and taking the Elder Wand, Grindelwald may have been trying to atone for his crimes. In Harry Potter and the Deathly Hallows – Part 1, young Grindelwald is portrayed by Jamie Campbell Bower while the older Grindelwald is played by Michael Byrne. In the film, unlike in the book, Grindelwald reveals to Voldemort the whereabouts of the Elder Wand.
Grindelwald appears in the Fantastic Beasts film series, portrayed by Johnny Depp in the first two films. In the film series storyline, Grindelwald and Dumbledore have made a blood pact in their youth to never harm each other which Grindelwald sports in a vial while seeking a means to indirectly kill his former lover. He first appears in Fantastic Beasts and Where to Find Them, though he is disguised for most of the story as the American Auror , played by Colin Farrell, while seeking out an Obscurus whom he learned to be Credence Barebone. In Fantastic Beasts: The Crimes of Grindelwald, Grindelwald manages to manipulate both Credence and Queenie Goldstein to his side by promising the former he will tell him who he really is (supposedly Aurelius Dumbledore, a long lost brother to Albus and Aberforth) and the latter that she will be free to marry her No-Maj fiancé, Jacob Kowalski. Campbell Bower reprises his role as the teenaged version of the character in a brief flashback scene as well. In November 2020, Depp resigned from the role at the request of Warner Bros. due to his personal legal troubles. Later that month, it was reported that Mads Mikkelsen was in early talks to replace Depp as Grindelwald for the third film. On 25 November 2020, Warner Bros. officially announced that Mikkelsen would replace Depp. On replacing Depp, Mikkelsen noted that it would be a "creative suicide" to copy Depp's "masterful" portrayal as Grindelwald, having developed his own take on the character, and admitted that a "bridge" should be needed between Depp's performance and his own, having been a fan of Depp since his early films.
In Fantastic Beasts: The Secrets of Dumbledore, Grindelwald attempts to get elected as the Supreme Mugwump of the International Confederation of Wizards. He has the incumbent Supreme Mugwump (and German Minister of Magic) Anton Vogel pardon him of his crimes and get him on the ballot late. He then enchants a dead Qilin (which recognizes those with pure hearts) to bow to him to sway the crowd to electing him. He is successful at doing this until his ruse is exposed by Credence Barebone and Newt Scamander and the dead Qilin's living sister is produced. When the new vote is called, she first bows to Albus Dumbledore and then to Brazilian witch Vicencia Santos, who is elected the new Supreme Mugwump. He attempts to kill Credence but the blood pact is broken in the crossing of spells. The two of them fight to a draw before Dumbledore turns his back on him. A distraught Grindelwald apparates away, signifying that the war has begun for good.