Their powers could be combined in a way where Ichigo's Zanpakuto spirit, Zangetsu, and Halibel's water - based powers merge. For example, Ichigo could gain the ability to use water - enhanced slashes that have the cutting power of his normal attacks along with the fluidity of Halibel's water attacks.
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.
One plot idea could be that Ichigo and Halibel are forced to team up against a new, powerful enemy that threatens both their worlds. They start off distrusting each other but gradually learn to respect and rely on one another's strengths.
For Ichigo, he could develop a more nuanced view of the Arrancars. Through his interactions with Halibel, he might realize that not all Arrancars are pure evil. This could make him more open - minded in his future encounters with other Hollows. As for Halibel, she could start to see the value in the Shinigami way, especially Ichigo's sense of justice. It might make her question her own loyalties and purpose.
Another theme could be the exploration of their different worlds. Ichigo is from the human world and Soul Society, while Halibel is from Hueco Mundo. Fanfictions might delve into how they bridge the gap between these two very different realms, perhaps through mutual understanding and cooperation. This can lead to interesting stories about cultural exchange in a sense, within the 'Bleach' universe.
In a post - war scenario, their relationship could develop into a mutual respect kind of thing. They've both seen the horrors of war, and they understand each other's strength. They might start to meet occasionally to exchange stories and advice on how to keep their respective groups safe.
Yes, there could be many fanfictions exploring different relationships between Ichigo and Halibel. Some might focus on their friendship, or them as allies in battles. Fanfiction writers often come up with creative scenarios that don't involve the more extreme or inappropriate concepts like pregnancy.
In fanfiction, the idea of Ichigo and Halibel having a baby can lead to very interesting stories. It would combine the unique powers and personalities of both characters. For example, the baby could inherit Ichigo's Shinigami powers and Halibel's Arrancar abilities, creating a truly powerful and unique being. This concept could also explore how the two different worlds they come from, the Soul Society and Hueco Mundo, would react to such a union.
To develop their relationship, start with small interactions. For example, the OC could save Halibel from a surprise attack by other Hollows. This would make Halibel curious about the OC. Then, have them exchange stories about their lives. Halibel could talk about her rise to become an Espada and the OC could share their origin story. Another way is to give them a common goal, like protecting a group of innocent Hollows from a cruel Arrancar. Working together towards this goal would bring them closer.
Romance is also a common theme. Writers like to imagine a relationship between Ichigo and Halibel, which can be a really interesting take considering their different personalities and allegiances in the original story. It can range from a slow - burn relationship to a more sudden and passionate one.