Hello, darlings! I'm also going to be following in the footsteps of
Mister Prewett and listing some headcanon stuff as it comes to me. I love to discuss characterisation, so feel free to drop a comment if you so desire.
1. To borrow from
Lucius: Bellatrix is incapable of producing an effective patronus. While she is capable of love, it isn't the kind of love that protects life.
2. It broke Bellatrix's heart when Andromeda chose to go against family wishes and marry a Muggle-born. Despite
being batshit insane her
harsh personality, she had always felt a deep connection with both her sisters and had sincerely hoped that Ted Tonks was merely a phase Andromeda would grow out of. It is from this heartache that the spite grew. It was much easier - on her - to be angry than to be sad.
3. Bellatrix loves her husband Rodolphus in her own way. Though perhaps it's closer to that of a pet more than a spouse. He is devoted to her, pure in blood, and the two seem to move as one on the field of battle. The two have been known to share brief moments of passion (that don't lead to anything in their marriage bed) after a particularly thrilling outing
1. She has full knowledge of, and even encourages him to seek comfort in the beds of other women. There is no doubt in her mind as to his unwavering loyalty to her. If she asked him to end any and all affairs, she firmly believes he would.
4. Though they are not lovers, had things been different and the two not been sentenced to Azkaban at the end of the First Wizarding War, Bellatrix would likely have borne Rodolphus children to continue the legacy and purity of their bloodlines. She's secretly jealous of what she perceives as the honour that was bestowed upon Draco when he was charged with granting the Death Eaters entrance to Hogwarts, and the assassination of Albus Dumbledore. While she is immensely proud of her nephew, she wishes it had been a child of her own. (And believes if it
had been her son, he would not have failed.
Malfoy blood made the boy a sissy.)
5. Believes half-bloods and mudbloods can serve their purposes, and be made useful, so long as they remember their place in the hierarchy. They make excellent
distractions as necessary.
6. A testament to her skill, Bellatrix was able to duel more than competently at the Battle of Hogwarts, despite the wand she was using not being her own. Due to the short amount of time she would have possessed it, it is very likely it was not yet loyal to her. She'll likely cite this as her reason for having been unable to hex Molly Weasley into oblivion, but in truth her defeat came at the hands of her own arrogance.
7. Fire affine. No, really. Bellatrix seems to totally love playing with fire.
1see also: Muggle massacre
More as I come up with it.