One idea could be to have Ichigo from 'Bleach' cross over into a world of a popular female - led anime like 'Sailor Moon'. He could team up with Sailor Moon to fight a new common enemy that threatens both their worlds. Their different fighting styles and powers would make for an exciting combination.
One possible plot could be that Ichigo, from the Bleach universe, accidentally stumbles into the world where fem Oga (presumably from Beelzebub) exists. They initially misunderstand each other's powers and motives. As they get to know each other, they team up to face a common enemy that is threatening both of their worlds. Maybe this enemy is a powerful demon who wants to absorb Ichigo's soul reaper powers and use Oga's connection to Beelzebub for its own evil plans.
First, decide which female character from another fandom you want to cross Ichigo with. Then, think about the setting. Will it be in the 'Bleach' universe, the other character's universe, or a new one? After that, come up with a basic plot. Maybe it starts with Ichigo accidentally ending up in the other character's world.
A powerful dark wizard could be the main antagonist. This wizard could be from a third, unknown dimension and is seeking to harness the combined powers of Ichigo and fem Oga for his own malevolent purposes. He might have the ability to manipulate dark magic and create illusions to deceive our heroes.
One popular 'byakuya x fem ichigo fanfic' could be 'A Bond Beyond Worlds'. It delves into how their different personalities, Byakuya's stoicism and Ichigo's fiery spirit, interact and gradually develop into a deep emotional connection. The story often has them facing various challenges together within the Soul Society and the human world.
Well, one aspect could be the exploration of the relationship dynamic between Ichigo and the female Hollow Ichigo. It might delve into how their opposing natures interact, like Ichigo's heroic side and the Hollow's more chaotic nature. It could also show how they influence each other's growth in the fanfiction world.
Another theme is the idea of breaking boundaries. In the context of the Soul Society, there are rules and hierarchies. A fanfic might focus on how their relationship defies these, like Byakuya being from a noble family and Ichigo being a human - turned - Soul Reaper. It's about them crossing those lines for love.
Power exploration is another theme. Writers often explore how fem Ichigo's powers interact with the powers or abilities in the crossover world. In a crossover with a superhero universe, she might compare her sword - fighting skills with a super - strength character.
One common theme is empowerment. Since Ichigo is female in these fanfics, a lot of them focus on her being strong and breaking gender norms in the Bleach universe. For example, she might be the first female Soul Reaper to achieve a certain rank or power level.