Aizen could also become more desperate. If his time travel is not going as planned, or if he discovers that changing the past has unforeseen and negative consequences, he may become more erratic in his actions. He could be constantly trying to fix the new problems he's created, leading to a more complex and unpredictable character development.
He might become more empathetic. Seeing the past versions of characters he once used or manipulated could make him question his own motives. He could start to value relationships more, rather than just seeing people as pawns in his grand scheme. For example, he might try to protect characters he previously endangered during his time - traveling adventures.
If Aizen time travels, his character could develop a sense of regret. Maybe seeing the destruction he caused in the future makes him want to change his ways in the past. He might become more empathetic towards others as he realizes the full impact of his actions.
One interesting plot could be Aizen traveling back in time to prevent his own downfall. He might use his knowledge of future events to outwit his enemies before they even become a threat. For example, he could manipulate the events that led to his discovery by the Soul Society, thus ensuring his continued rise to power undetected.
The storyline could start with Naruto somehow ending up in Aizen's world. At first, he would be confused and on guard. But as he gets to know Aizen, he might see some potential in him. Naruto would try to change Aizen from the inside. Aizen, on the other hand, might see Naruto as a useful tool or an interesting experiment.
In a time - travel situation, Orihime could have a chance to understand Ulquiorra better. She might see his past and the events that shaped him into the being he is in their original timeline. This new understanding could lead to a deeper emotional connection between them. She could start to see him not just as an enemy but as a complex being with a tragic past, which would change the way she interacts with him.
The Soul Reapers would be very confused at first. They are used to Aizen being a certain way, and Naruto's different personality would be a shock. Ichigo might be curious and see Naruto - Aizen as an ally against the common enemies. Orihime could be one of the first to trust Naruto - Aizen because of his kind - hearted nature that she would sense. And the Espadas would probably be on high alert, not knowing what to expect from this new Aizen.
Sarada's character might develop a greater sense of empathy. When she travels back in time, she sees the struggles and hardships of the past. For instance, if she goes back to a time when the village was recovering from a great war, she would understand the sacrifices made by previous generations. This newfound understanding could make her more empathetic towards others in her own time as well. Also, she could become more confident in her abilities as she has to adapt to a different environment and challenges during her time - travel journey.
Naruto would probably be very cautious around Aizen at first. He's used to facing powerful enemies, but Aizen's deceptive nature would be a new challenge. Aizen, on the other hand, might see Naruto as an interesting specimen, someone with a strong will and great power that he could potentially manipulate.
If Tsunade time travels, she might become more cautious. Seeing the past mistakes of the village, she'd be more careful in making decisions in the present. For example, if she saw how a certain policy led to problems in the past, she'd oppose similar ones in her own time.
If Anakin time travels, his character could become more self - aware. He might see the mistakes he made in his original timeline and become more cautious. For example, if he travels back to a time before his relationship with Padmé started, he could handle his emotions better and not let his fear of losing her drive him to the dark side.
One interesting 'Bleach Female Aizen Fanfiction' could be where she has to navigate the complex power structure in Soul Society differently from the male Aizen. Maybe she uses her charm more subtly to gain allies. Another aspect could be how her relationships with other characters, like Ichigo, would change. Since she's female, the dynamic might be more of a mentorship or a different kind of rivalry.