She could go back in time to meet Tom Riddle when he was still a student at Hogwarts. This would be an interesting encounter as she could try to influence him in different ways compared to what actually happened in the original story.
In a time - travel Bellatrix fanfic, she might go back to the time when she was first introduced to the Dark Arts. This could show a different side of her, perhaps a more innocent - looking but still dark - inclined Bellatrix. She could interact with younger versions of other Death Eaters and form different alliances that change the course of the future in the wizarding world.
In the fanfic, Bellatrix might use her magic to protect Harry from his abusers. Maybe she realizes the wrongness of the abuse and decides to be his unexpected savior. She could use her dark magic skills to intimidate those who harm Harry, creating a sort of dark - but effective - protection around him.
One possible fanfiction could involve Bellatrix going back in time to try and change the outcome of the Battle of Hogwarts in her favor. Maybe she uses time - turners or some dark magic to travel back. She could attempt to kill Harry Potter as a baby before he even becomes a threat.
In such a fanfic, Bellatrix might use dark magic or psychological torture to drive Harry insane. She could target his memories of his parents or friends, causing him to lose his grip on reality.
In a Harry Potter fanfiction where Bellatrix Lestrange joins, she could be a major source of conflict. She's extremely skilled in the Dark Arts. Her addition to the story might see her influencing the plot in ways that are both unpredictable and dangerous. For instance, she could manipulate other characters, especially those on the darker side of the wizarding world. She might also introduce new magical elements or artifacts that are related to the Dark Arts. Her character is so complex and unpredictable that she could either be a pure antagonist or, in a more creative take, have a change of heart and become an anti - hero, but this would require a very well - written and thought - out plot.
Perhaps Harry travels back in time and tries to befriend Draco before he becomes so antagonistic. He could show Draco the error of his ways early on, like how being mean to others isn't cool. This could lead to Draco being a more positive influence in Slytherin house instead of causing trouble.
Bellatrix Black, in a fit of desperation to change the outcome of the Battle of Hogwarts for the Death Eaters, stumbled upon a time - travel spell. She traveled back to the time when Harry Potter first arrived at Hogwarts. She planned to kill him right away, but she was thwarted by Dumbledore, who seemed to sense something amiss. Dumbledore, with his great power, managed to trap Bellatrix in a time - loop for a while until she finally managed to break free. But by then, she had missed her chance to harm Harry and had to return to her own time, realizing that time itself was a powerful force that couldn't be easily manipulated.
Well, Harry might find himself in a time when James' brother was at Hogwarts. He could witness their school days and how the family dynamics were different back then. Harry could form an unexpected friendship with James' brother, which would give him new insights into his father James and the entire Potter heritage.
Well, he might find a world where magic has been completely integrated with Muggle technology. For example, broomsticks are now used for inter - planetary travel and there are magical apps on smartphones. Also, Hogwarts could be a much larger and more diverse place, with students from all over the universe coming to study.
She could travel back to the time when Voldemort was still in hiding as a young Tom Riddle. Bellatrix might try to influence him in a different way, perhaps making him even more ruthless. This would change the course of the wizarding world in a very different direction.