Bellatrix Lestrange is irredeemable as a villain. Twisted, demented and loyal to Harry Potter’s most feared adversary Lord Voldemort, she is someone to be feared.
The cousin of Sirius Black, the sister of Andromeda Tonks and Narcissa Malfoy, and the aunt of Draco Malfoy, Bellatrix is a nasty piece of work. She has murdered and tortured people for fun and doesn’t feel remorse for her actions. Her loyalty to Voldemort is the whole reason she ended up in Azkaban.
The Black family was full of incest, with cousins marrying cousins because they were obsessed with blood purity. Bellatrix married Randolphus Lestrange, despite not loving him. Her complete devotion was to Voldemort, and she bore her master a daughter, Delphini, though he never had any ounce of love in him.
Bellatrix was deeply in love with Voldemort and was one of the few who remained devoted to him while he didn’t have a body. But, unfortunately, she was also incredibly sadistic. She tortured Frank and Alice Longbottom, the parents of Neville Longbottom, to the point they didn’t recognise their son, who had to live with his grandmother. She wanted information but was unable to break their minds.
Order Of The Phoenix Film
As witnessed in the Order of the Phoenix film, Neville knows what happened between Bellatrix and his parents. So he wants revenge when she taunts him during the Battle of the Department of Mysteries.
Neville tells Harry that he’s proud to be Frank and Alice’s son, but he’s not ready to tell anyone yet.
In conclusion, Bellatrix sees her cousin Sirius as a blood traitor and has no time for her niece, Nyphadora. So she murdered both of them and felt no guilt.