Well, perhaps in the fanfic, female Ichigo betrays her allies because she has been brainwashed. Some sort of evil entity or powerful Quincy could have gotten into her head and made her believe that her friends are the real enemies. So she begins to pass on their secrets and even attacks them, leading to a lot of chaos and heartbreak among her former friends.
There could be Byakuya. He would be shocked and disappointed by female Ichigo's betrayal as he might have seen her as a promising comrade. Also, Rukia. Since she and Ichigo have a special bond, her reaction to Ichigo's betrayal would be very emotional. And then there's Aizen. He could be the one who tempted or manipulated female Ichigo into betraying, seeing her as a useful pawn in his grand schemes.
One character that might betray Ichigo is Chad. In some fanfic scenarios, if Chad is corrupted by some dark force or if he discovers some 'truth' about Ichigo that he believes is a threat to the world, he could turn on him. Also, Orihime has the potential to be a betrayer in fanfictions. If she is brainwashed by an enemy, like a powerful Hollow or an evil Quincy, she could be made to act against Ichigo. Her powers are unique and if misused, could cause a lot of harm to Ichigo.
Ichigo would also experience a period of sadness. He values his relationships, and when one is broken through betrayal, it would hurt him deeply. He might isolate himself for a while, brooding over what happened. But ultimately, he would use this experience to become stronger. He'd learn from it and be more cautious in future relationships, while still maintaining his core values of loyalty and trust.
Well, sometimes in these fanfics, Ichigo is betrayed by his Hollow side. It could be that the Hollow part of him has its own agenda and decides to use Ichigo's friends as bait to draw out more powerful opponents. This would make Ichigo feel extremely guilty as he's the one who brought this danger to his friends. Also, there could be a plot twist where Ichigo is betrayed by a new character introduced in the fanfic. This new character might have pretended to be his ally all along but was actually working for a powerful antagonist. This would make Ichigo realize that he can't trust people so easily.
Ichigo might go into a state of self - reflection. He would wonder if there is something he has unknowingly done to cause this. He would try to analyze his past actions during the time travel. He might isolate himself from his so - called betrayers for a while to think things through. But ultimately, he would not give up on his friends. He would strive to find a way to regain their trust and set things right, because he values his relationships with them deeply.
First, you need to have a clear understanding of Ichigo's character. Know his strengths, weaknesses, and what makes him tick. Then, when it comes to the time travel aspect, establish the rules early on. For the betrayal part, create a believable reason for why someone would betray Ichigo. It could be related to power, love, or some hidden agenda. Make sure the plot progresses logically and that Ichigo's reactions are in line with his character. Also, don't be afraid to add some twists and turns to keep the readers interested.
One possibility could be that Ichigo is betrayed by a close friend during his time - traveling adventures. Maybe this friend is jealous of Ichigo's powers or has been influenced by an enemy. This betrayal could lead Ichigo to question his relationships and his purpose in the time - traveling journey. He might then have to find a way to overcome this betrayal and still fulfill whatever mission he has in the different time periods.
One common theme is empowerment. Female Ichigo is often depicted as strong and capable, breaking through gender barriers in the Soul Society. Another theme is self - discovery. She explores her powers and identity.
I've heard of a fanfic called 'The Blue and the Orange'. In this, the author does a wonderful job of portraying female Ichigo's strength and how it catches Grimmjow's attention. It's set in a post - war scenario where they have to team up against a new threat. It's full of action and also has some sweet moments between the two characters.