Common themes include power dynamics. Bellatrix is a powerful Death Eater and Sirius is a powerful wizard too. Their interactions in fanfiction often involve a struggle for power or a mutual respect for each other's power. Also, the theme of redemption can be seen sometimes, where Bellatrix might be swayed from her dark path by Sirius. It's also not uncommon to see themes related to family, as they both come from prominent wizarding families.
One common theme is the exploration of good vs. evil within their relationship. Since Sirius is on the side of good and Bellatrix on the side of evil. Another theme could be the idea of forbidden love, as their different loyalties would make a relationship between them extremely difficult in the context of the 'Harry Potter' world.
The themes in Bellatrix Lestrange x Sirius Black fanfiction are quite diverse. There is often the theme of the 'what if' scenario. What if they had met under different circumstances? There is also the theme of emotional conflict. Bellatrix is a rather unhinged character and Sirius has his own emotional baggage. Their relationship in fanfiction can be a study in how these two complex characters deal with their emotions towards each other. And of course, the theme of the clash between different magical ideologies, with Sirius representing the Order of the Phoenix and Bellatrix the Death Eaters.
Chapter 340, "Holy Heart Hospital", is the clearest early answer because it turns Li's situation into a concrete plot event. Early on, Wen," Lin Manru said quickly, her face full of gratitude.. By the end, But now, she could fully trust her daughter..
Chapter 409, "I'm Feeling Lucky!", is the clearest early answer because it turns Jiang Yan's situation into a concrete plot event. It opens with Jiang Yan was still arguing with Yu Li with his hands on his hips,...
Chapter 670, "Sister Will Support You", is the clearest early answer because it turns Gu's situation into a concrete plot event. The chapter gives readers a real answer by opening on Jiang Li, sensing that something might have gone wrong, quickly used...
Chapter 575, "The First Time Threatening Someone Feels Quite Marvelous", is the clearest early answer because it turns President Zhao's situation into a concrete plot event.
Chapter 310, "Sister, Eat More", is the clearest early answer because it turns Jiang Yan's situation into a concrete plot event. The chapter gives readers a real answer by opening on Jiang Yan snorted, "Then, Grandpa, you just talk less, so Uncle Three...
Chapter 646, "This person deserves a slap in the face!", is the clearest early answer because it turns Jin Siyue's situation into a concrete plot event. It opens with Jiang Yan: "....." Bloody green tea, get lost! and closes on You won't be at a disadvantage." Zhao Lang's lips curled up a bit,....
Chapter 668, "This is my son, Chen Qijun!", is the clearest early answer because it turns Wen Feifei's situation into a concrete plot event. The chapter gives readers a real answer by opening on The guitarist explained seriously, "This is not just any guitar; it's...
Chapter 233, "Individual, Ten, Hundred, Thousand... Million, Ten Million, Damn!!!", is the clearest early answer because it turns Individual's situation into a concrete plot event. A useful checkpoint is the way the scene starts with [What the hell, what's this about life span ending??
Chapter 614, "Storm Crisis", is the clearest early answer because it turns Jiang Yan's situation into a concrete plot event. The chapter turns that into something concrete by moving from Today, the wind on the island was stronger, and for safety reasons,...
Chapter 663, "How Did These Two Start Fighting?!", is the clearest early answer because the buildup finally cashes out in a real clash. A useful checkpoint is the way the scene starts with Jiang Shixu received the message in daylight the next day.