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.
A plot might involve Chappy and Ichigo teaming up to solve a mystery in Karakura Town. This could involve strange spiritual disturbances that only their combined skills can figure out. They might also meet new characters during this adventure, characters that could potentially become allies or enemies in the future. It could be a story full of twists and turns as they try to piece together the mystery.
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.
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.
One interesting plot is when Ichigo has to balance his Shinigami and Quincy powers. It creates a lot of internal conflict for him, which makes for a great read.
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.
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.
A possible plot development could be Ichigo being made to fight against his former allies. Under the brainwashing, he might believe that his friends are actually his enemies. Another development could be Xcution trying to extract Ichigo's power while he's in this brainwashed state.
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 He might become more withdrawn and focus even more on his battles and training, using it as an escape from the pain of the betrayal.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 development could be Ichigo struggling to control his Hollow powers. He might accidentally harm his friends, like when he first started to gain his Soul Reaper powers. This internal battle could lead to him isolating himself from his allies in an attempt to protect them. Another aspect could be his appearance changing more towards the Hollow form, which might cause others to fear or be distrustful of him.
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.
Perhaps a plot where Ichigo accidentally ends up in Hueco Mundo near Halibel's territory. She initially sees him as a threat but then discovers that he has no intention of harming her or her fracciones. This could lead to an exploration of their different worlds and cultures within the Bleach universe.