Rukia would probably be both amazed and a bit worried. Amazed at the new power Ichigo has, but worried about how it might change him. Chad would see it as a natural progression of Ichigo's power and be supportive. Orihime might be a bit scared at first, but then she would see the good in Ichigo's new form and try to encourage him.
The Soul Reapers in the Soul Society would see Ichigo as a major threat. They would likely mobilize their forces to either capture or eliminate him. Captains like Byakuya would be disappointed as he had come to respect Ichigo to some extent, and now would see him as a traitor.
Rukia would probably be one of the first to be both shocked and amused. She might tease Ichigo a bit at first but then quickly get serious about helping him. Chad would be very accepting and offer his protection as usual. Uryu might be a bit more skeptical at first, thinking it's some kind of new Hollow trick. Orihime would be very empathetic and try to make Ichigo feel comfortable in his new form, maybe even offer to make some new clothes for him to fit his new body.
Rukia would be extremely shocked and disappointed. She has always seen Ichigo as a force for good, and seeing him side with Aizen, who is the main antagonist, would be a huge blow to her. She might try to talk Ichigo out of it at first, and if that fails, she could become his enemy.
Another idea for the fanfiction could be a time - travel plot. What if Ichigo somehow travels back in time and meets a younger Rangiku? He could influence her growth and development, and in turn, she could have an impact on his view of the past. This would create a complex web of cause and effect, and it would be interesting to see how their actions in the past would shape the future of the Bleach world they know.
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.
One great aspect of Bleach Ichigo and Rukia fanfiction is the exploration of their relationship beyond the original story. Writers often delve into their deep bond, showing how they support each other in different situations. It could be in the face of new threats in Soul Society or just in their daily lives. Fanfiction gives a chance to expand on their characters and how they interact, which is really interesting for fans of the series.
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.
A significant factor in their relationship growth in fanfiction could be the influence of their friends. Their friends in Bleach, like Uryu or Chad, might notice the budding relationship between Ichigo and Orihime. Their reactions and support can play a role in either accelerating or complicating the relationship, adding more depth and realism to the fan - created story.
A fanfiction could also explore how they deal with loss together. Both have experienced losses in their lives. They could find solace in each other's company and share their stories of grief. This would create a very emotional bond between them. It could also lead to a moment of self - discovery for both characters as they see how the other has coped with difficult situations.