One possibility could be that during his time travel, Ichigo discovers that his friends or allies in the future have turned against him for some reason. Maybe they believe he has become too powerful and is a threat. So they plot to betray him, which sets up a conflict where Ichigo has to fight against those he once considered friends while also trying to figure out a way to fix the timeline.
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.
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 possible plot could be that Ichigo gets sent back in time accidentally due to some of Kisuke's experiments gone wrong. He then has to figure out how to get back to his own time while also dealing with the past versions of his friends and enemies. Kisuke, of course, feels responsible and tries to help him.
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.
Perhaps the time travel is not what it seems. It could be a trap set by an unknown enemy. When Ichigo and Unohana think they are traveling through time to fix something, they are actually being led into a situation where they will be separated and used against each other. This would create a lot of drama and conflict in the fanfiction.
Well, perhaps in this fanfiction, Percy Jackson is sent on a time - travel mission by the gods. But he discovers that his friends or allies have betrayed him. Maybe they've made a deal with an enemy from another time period. For example, they could have promised to help Kronos in the past in exchange for power in their own time. Percy then has to not only deal with the time - travel chaos but also face the betrayal and find a way to set things right.
Perhaps Harry Potter travels back in time and, for some reason, makes a deal with the dark side. He might be tricked into believing that by siding with Voldemort in the past, he can save more lives in the future. This betrayal could lead to a whole new chain of events, changing the relationships he has with his friends like Ron and Hermione.
Well, it could be about Percy finding out that a god he trusted has betrayed him. Maybe this god has been using Percy for their own gain all along, like in battles against other gods or monsters. Percy would then have to deal with the shock and figure out how to either get revenge or make things right in the world of the gods.
A really cool plot twist would be if during their time travel, they find out that time itself is a sentient being or is being controlled by an unknown force. This force has been manipulating events in the Soul Society and the human world all along. Ichigo and Urahara then have to figure out how to deal with this new discovery, whether to fight it or try to negotiate, while also trying to find their way back to their own time.