As mentioned in the book, Dumbledore was 'the only one he ever feared'. Deep down, Voldemort knew that Dumbledore was more powerful than him. He had superior magical capability and possessed important information about Voldemort.
Besides Dumbledore, he is also the only wizard ever known to be able to apparate silently. Voldemort was also said to fear one wizard alone, Dumbledore.
Lord Voldemort is one of the most feared and powerful wizards. He is known for his cunning and ruthlessness. Formerly known as Tom Marvolo Riddle, Lord Voldemort was the most formidable evil wizard in the entire universe.
Throughout the Harry Potter series, we are led to believe that Dumbledore is one of the only people Voldemort actually fears; and for good reason. Albus Dumbledore is a well known and very powerful wizard in the Harry Potter series.
Voldemort fears Dumbledore because he knows Dumbledore is more powerful than him, having known Dumbledore and Grindelwald's duel in 1945, and he had just finished school that time. Voldemort feared suffering the same fate as Grindelwald.
Bellatrix Lestrange (née Black) is the first female Death Eater introduced in the books. Aunt of Draco Malfoy and Nymphadora Tonks. She was introduced in Harry Potter and the Order of the Phoenix. She is the most faithful member of Voldemort's inner circle.
Voldemort's greatest fear is death and as a result a boggart takes the form of his own corpse. It is unsurprising that this is Voldemort's biggest fear. After all, he did split his soul up encasing it in various horcruxes just so to keep himself from dying.
She seemed to have a sick obsession with Voldemort that went so far beyond romantic desire. She was also very clearly scared of him and his remarkable magical abilities. However, the reason for her obsession clearly went a lot deeper and probably had to do with the relationship that she had with her parents.
Harry Potter, I now speak directly to you. On this night, you have allowed your friends to die for you rather than face me yourself. Lord Voldemort : There is no greater dishonor. Join me in the Forbidden Forest and confront your fate.
He hated his father for being a muggle, leaving his mother and her heritage, etc. Voldemort hated Dumbledore because he (Dumbledore) was his (Voldemort's) rival. Voldemort hated (or more feared and disliked) Harry because he (Harry) was his doom.
Grindelwald Is More Powerful and Cunning Than Voldemort
Grindelwald had more power in the Wizarding World up till the final moments of his life. He had more followers, and they were intensely loyal to him. He conquered more of the globe and could perform more advanced forms of magic.
Dumbledore may have been a legendary wizard, but he can't be compared to, well, Merlin, a wizard so legendary even Muggles know of his exploits. Merlin was the world's most famous wizard, and, arguably, the world's most powerful.
But in a toss-up between the Hogwarts headmaster and his young protégé, Dumbledore comes out on top. Think about it: he won every award as a student, while Harry just squeaks by; he founds the Order of the Phoenix long before Harry ever joins; and he teaches young Harry pretty much everything he knows.
Like Tom Marvolo Riddle (aka Voldemort), Merlin was a Slytherin, an ambitious, powerful wizard. He was a wizarding legend, and, of course, more powerful than the Dark Lord. According to the Harry Potter Wiki, Merlin was “arguably one of the most powerful wizards of all time”.
Albus Dumbledore
It is not certain what the specific fear is as he is not fearing the death of his sister as she is already deceased and it is suggested that Dumbledore fears that it was him who directly killed his sister in the conflict or that he fears the loss of control that lead to his sister's sudden death.
"There Is No Good And Evil. There Is Only Power And Those Too Weak To Seek It." Voldemort is not voiced by Ralph Fiennes in The Philosopher's Stone, but rather by the man who performs Professor Quirrell, Ian Hart, who delivers this brilliant line that accurately sums up his character.
"Hagrid is one of Voldemort's oldest associates, and knows his true identity" In Chamber of Secrets, it is revealed that Hagrid had been a student at Hogwarts during the same period that Tom Riddle (the true identity of Lord Voldemort) also frequented the school.
Voldemort can not comprehend love, and so it destroys him to touch Harry because Lily's love for her son runs through Harry's veins and body. ems Harry burnt Quirrell's face when he touched it.
Cruciatus Curse ('Crucio')
Harry tried to use this spell himself. The first time was against Bellatrix after she had killed Sirius. His attempt was unsuccessful because, as Bellatrix mockingly explained: 'You need to really want to cause pain – to enjoy it – righteous anger won't hurt me for long…'
His reaction to Bella's death was akin to his reaction at the loss of the Cup, which was when he realised that his own immortality was jeopardised amidst war and his own death could have been near.
Bellatrix Lestrange Killed her own cousin, Sirius Black: She killed Sirius (who was her cousin) during the battle at the Department of Mysteries. She was remorseless and was cackling in glee after she had murdered Sirius.
On Lord Voldemort as a psychopath or sociopath
“There are psychologists who would argue there's really no difference, and in fact, if you consult the diagnostic manual, it would really lump them under one category, antisocial personality disorder.
Draco Malfoy - Voldemort
In this game, it becomes clear that Draco Malfoy's Boggart is Lord Voldemort. Draco's fear of Voldemort likely comes from different reasons than others have. Most fear Voldemort taking over the world. Draco fears Voldemort intimidating and manipulating the Malfoy family.
Voldemort's weaknesses are arrogance, aforementioned fear of death, and total disregard for things that he does not understand, all of which eventually contribute to his downfall.