One possibility is that it could be a genetic anomaly. Maybe something in his Saiyan genes that was dormant suddenly activated, causing the tail to grow back. In the Dragon Ball universe, Saiyan genetics are complex, and there could be some unexplored factors at play.
Well, in Dragon Ball lore, Gohan's tail was a Saiyan trait. In this fanfiction, it might mean he has more access to his Saiyan instincts. Maybe he can transform more easily into a Great Ape or use some of the primal Saiyan powers that were associated with the tail.
Another possibility is that the kid is from an alternate dimension where time passes differently. Natsu's kid shows up in the Fairy Tail world and he has to figure out how to be a father. The story could focus on their journey to get to know each other and the kid's adjustment to this new world.
In fanfiction, the relationship between Kagome and Naraku can be very complex. Some fanfictions might explore the idea of Naraku having unexpected feelings for Kagome or vice versa. It could be a way to rewrite their antagonistic relationship in the original work and give it a new twist.
One way to replace Kagome in a fanfiction with an Original Character (oc) is to first analyze Kagome's role in the story. What are her personality traits, relationships, and goals? Then, create an oc with similar but distinct qualities. For example, if Kagome is brave and kind-hearted, your oc could be equally brave but perhaps more reserved in showing kindness. Next, go through the fanfiction and systematically replace Kagome's actions, dialogue, and interactions with those of your oc. Make sure to adjust the reactions of other characters accordingly to fit the new dynamic. This process might take some time and careful consideration to ensure the story still flows well and remains engaging.
Bankotsu and Kagome fanfiction is interesting because it combines two very different characters. Bankotsu is often seen as a rough and tough warrior, while Kagome is more gentle and spiritual. A fanfiction could play on this contrast, for example, having Kagome's kindness soften Bankotsu's hard edges.
At first, Kagome is likely to be angry. She's a strong - willed character, so being kidnapped goes against her nature. She would probably struggle and try to escape immediately, yelling at Koga about how wrong his actions are.
Kagome would probably be shocked at first. Then she would start yelling at Inuyasha, demanding to know why he's doing this. She's not the type to just sit there and take it.
Inuyasha can be really interesting in this context. His reaction to Kagome's transformation into a Dark Miko would be complex. He's used to the normal Kagome, so seeing her change might make him both worried and a bit on edge. He could try to bring her back to her old self while also being in awe of her new power.
Inuyasha would likely become more protective. He's always been protective of Kagome, but with her pregnant, it would be on a whole new level. He might not let her go on dangerous missions as easily. Kagome, on the other hand, would probably get frustrated with his over - protectiveness at times, but also appreciate his concern deep down.