Obviously Lana herself is the central character. Her Pokemon partners are very likely to be involved. For example, Popplio might be constantly by her side, providing emotional support. Ash and his Pikachu could also be part of the story. Ash, being a good friend, would probably offer his help and advice. Misty might also be there, sharing her own experiences or just being a good friend to Lana during this time. Brock could be involved too, perhaps using his knowledge of Pokemon and nature to ensure Lana has a healthy pregnancy. And other trainers from the Pokemon world who are friends with Lana might make appearances to show their support and be part of the story.
Team Rocket could also be involved in an interesting way. Instead of their usual villainous antics, they might accidentally find out about Lana's pregnancy and have a change of heart. Maybe they end up helping Lana in some unexpected ways, like providing rare items or information that could be useful for her pregnancy. Or they could be the source of some trouble, trying to use her pregnancy to their advantage in a misguided way. Other Pokemon trainers from different regions who have heard about Lana's situation might also come to visit or offer their assistance, adding more diversity to the cast of characters in the fanfiction.
The Pokemon Center nurses would be important characters. They could be the ones providing medical check - ups and advice to Lana during her pregnancy. Nurse Joy in particular would play a crucial role. Lana's family members, if they exist in the fanfiction, would also be involved. Her parents or siblings could come to visit her or be part of the preparations for the new baby. And there could be some new characters introduced, like a special Pokemon expert who has knowledge about how pregnancy can affect a trainer's bond with their Pokemon. This expert could offer unique insights and help Lana through this special time.
Obviously, Octavia herself is the central character. Her brother Bellamy is likely to be involved. He would probably be very protective of her and the unborn child. Clarke might also be part of the story, perhaps providing medical knowledge or just being a friend to Octavia during this time.
Well, obviously Juvia herself is the central character. Her partner would also be very involved. If it's in the context of Fairy Tail, Gray would likely be her partner in the fanfiction, as they have a strong relationship in the original series. Then there are their friends like Lucy, Natsu, and Erza. They would probably be there to support Juvia during her pregnancy, offer advice, or just be there for the big moments.
Her colleagues at her firm like Abby, Huck, and Quinn are likely to be involved. They could be her support system, helping her with her work while she's dealing with the pregnancy. Or they could get caught up in the drama that her pregnancy might bring, like having to cover for her more often or deal with the media frenzy that might occur if the pregnancy becomes public.
Obviously Jules herself is the central character. Her partner, if she has one in the Flashpoint story, would be very involved. They would be there for her during doctor visits, shopping for baby things, and all the emotional moments.
Another character that could be involved is Charlie, Bella's father. His reaction to his daughter being pregnant in the strange world of Eclipse could be a significant part of the story. He might be confused, worried, or try to protect Bella in his own way. Also, some of the werewolf pack members aside from Jacob could also make appearances and contribute to the story based on their relationships with the vampires and Bella.
Obviously Lauren herself is the central character. Her family members like her parents would likely be involved. They might have different reactions, with her mother being more nurturing and her father perhaps being more concerned about the family's reputation.
Also, any friends that Renesmee has made throughout her life could be involved. They might be there to offer moral support, or there could be some who are jealous or envious of her situation, which could add some drama to the fanfic.
Definitely Ash, as he's the center of Serena's affections. But also, there could be new female characters created specifically for the fanfiction. These new characters might be trainers who are really good at Pokemon battles and catch Ash's attention. Serena would then become jealous of their skills and the attention Ash gives them. Additionally, any of Ash's Pokemon that seem to have a special connection with another character could also be part of the scenario that makes Serena jealous. For example, if Pikachu seems to like a new girl more than Serena, that could be a reason for her jealousy.
The Lone Wanderer is likely to be involved. They have a pre - existing relationship with Amata from the game. Her father, the Overseer, might also play a role, either in supporting or opposing the situation. Other characters from Megaton or Tenpenny Tower could potentially be involved as well.
Finn could be involved if the fanfiction wants to explore a relationship with him as the possible father. He was an important part of Rachel's life in the original series, and his reaction to the news would be significant.