One possible reason could be to gain more power. In the Bleach universe, the dead often possess unique powers or knowledge. By raising the dead, Ichigo might be seeking to learn from them or use their power to fight stronger enemies.
It could also be a result of some unforeseen consequence of his own power evolution. His Hollow powers or his Shinigami powers might have developed in an unexpected way, leading to this ability to raise the dead. And he might be using it to change the balance in the spiritual world in some way.
Ichigo may grow in power and confidence. As he masters the ability to raise the dead, he could use it to his advantage in battles, which would boost his confidence and also lead to further development of his combat skills and strategic thinking.
One possible reason could be that Tsukishima is under some sort of mind control or influence from a more powerful and malevolent force. Maybe he has been deceived into believing that Ichigo is a threat to something he holds dear.
Maybe Ichigo's death occurs due to a curse that he unknowingly activated. In the fanfic, this could lead to a whole new set of rules in the Bleach universe. His friends might then have to search for a way to break the curse and resurrect him. It could involve traveling to unknown realms or making deals with mysterious entities.
Ichigo would probably be devastated. His trust in relationships would be severely shaken. He might become more withdrawn and focus even more on his battles and training, using it as an escape from the pain of the betrayal. He could also become more cynical about love and people in general.
One possible plot is that Chappy accidentally gets lost in the human world and Ichigo has to find her. Along the way, he discovers some new secrets about the Soul Society or his own powers. Another plot could be that Chappy gets kidnapped by an enemy, and Ichigo embarks on a dangerous rescue mission, facing powerful foes he has never encountered before.
There's a fanfic called 'The Bond of Hearts'. It's set in an alternate universe where Ichigo and Orihime are childhood friends. It shows their relationship evolving over the years. It delves deep into their emotions and how they gradually realize their love for each other. The character development in this fanfic is quite engaging.
In a Bleach Ichigo hot spring fanfic, Ichigo could be on a mission near a hot spring. He decides to take a break and soak in it. While there, he overhears some important information from other characters who also happen to be at the hot spring. This information could be crucial for his mission, and he has to figure out how to use it without blowing his cover.
Perhaps the fullbringers are being controlled by a new, unseen enemy. This enemy wants Ichigo out of the picture, so they use the fullbringers to brainwash him. Ichigo, while brainwashed, starts to cause destruction in the Soul Society. His actions draw the attention of the Soul Reapers, who are initially unaware that he's been brainwashed. As the story progresses, some of the more perceptive Soul Reapers figure out what's going on. They then team up with Ichigo's friends from Karakura Town to find a solution. This could involve a lot of exploration of Ichigo's mind and his past relationships to find the key to breaking the brainwashing.
In this fanfic, perhaps it focuses on the friendship between Chappy and Ichigo. Chappy might help Ichigo in some unexpected ways. For example, Chappy could use her unique abilities to guide Ichigo through a difficult part of Hueco Mundo. Their bond could also be a source of strength for Ichigo during tough battles, giving him an extra boost of motivation.
Well, it could be about their adventures together after the main events in Bleach. Maybe they go on a mission to a new realm and face new enemies while strengthening their bond as friends and comrades.