Well, Bellatrix is a very complex and cruel character. In the fanfiction context, she might torture Draco to assert her dominance. She is a powerful and deranged Death Eater, and by torturing Draco, she can show that she is in control. Also, it could be related to her pure - blood mania. If she thinks Draco is not living up to the pure - blood standards in some way, she may take it upon herself to 'correct' him through torture.
In some fanfictions, Bellatrix's motive for torturing Draco could be related to her own instability. She is a bit of a loose cannon in the Death Eater ranks. Torturing Draco could be her way of relieving her own frustrations or simply because she enjoys causing pain. She may also see Draco as a weak link in the Death Eater chain and want to toughen him up in the most extreme way possible, not realizing or caring about the long - term psychological damage it may cause.
One possible motive could be jealousy. Bellatrix is extremely loyal to Voldemort, and Hermione is a very powerful and intelligent witch from the side opposing Voldemort. Bellatrix might see Hermione as a threat and also be jealous of the attention Hermione gets from Harry and Ron. So, she tortures Hermione to try and break her spirit and prove her own superiority.
Sure. There could be. For example, in some fanfictions, the 'torture' might be more of an emotional or mental kind. Bellatrix could use her intimidating presence and cruel words to torment Draco. This type of story can be interesting as it delves into the complex family dynamics within the Death Eater world. It can show how Draco tries to cope with such a difficult situation, perhaps by seeking help from unexpected allies like some of the Hogwarts students who oppose the Death Eaters.
One possible motive could be Bellatrix's loyalty to Voldemort. She might think that by kidnapping Hermione, she can get information about Harry Potter and the Order of the Phoenix. Hermione is known to be very intelligent and Bellatrix could believe she has valuable knowledge. For example, Hermione might know the location of Potter or the Order's plans against Voldemort.
Another motive could be related to Bellatrix's loyalty to Voldemort. Maybe she suspects Hermione of something, and this is her way of getting a reaction out of her. She could be trying to unnerve Hermione to see if she gives away any secrets or shows signs of being involved in something that Bellatrix or Voldemort would be interested in.
One possible motive could be revenge. Bellatrix killed Sirius, who was very dear to Harry. So in the fanfiction, Harry might be driven by the intense desire to avenge Sirius' death.
Draco could be seeking redemption. He may be tired of being on the wrong side of the war. Saving Hermione, who is a symbol of the good side, would be a significant step in his journey towards redemption. Additionally, he might be influenced by his friendship or alliance with some of the other characters who are on the side of the Order of the Phoenix. They could have convinced him to do the right thing and save Hermione from Bellatrix.
One common theme is the exploration of dark magic. Since Bellatrix is a known dark witch and Draco was on the verge of fully embracing the dark side, fanfictions often look into how dark magic affects their relationship and individual characters. For example, in some stories, Draco might be tempted by the same kind of magic Bellatrix uses.
It depends on how the author writes it. If it's very graphic and violent, it might not be suitable for younger readers. But some authors can handle the dark theme in a more tasteful and less disturbing way.
One reason could be pure hatred. Bellatrix despises Muggle - borns, and Hermione being a very intelligent and powerful Muggle - born would be a prime target for her wrath. Another could be jealousy. Hermione's skills and knowledge might make Bellatrix feel inferior, leading her to lash out.
You can try fanfiction websites like FanFiction.net or Archive of Our Own. Just search for 'Hermione tortured by Bellatrix' in their search bars.