The main characters are clearly Lydia and Aiden. Since it's a pregnant fanfiction, they are likely the couple who are going to experience the journey of pregnancy together.
In the fanfiction, it could be that the pregnancy is a turning point in their lives. Lydia and Aiden could be part of a fantastical world where the pregnancy has some special meaning or power. For example, the baby could be prophesied to bring great change to their world. So they not only have to deal with the normal aspects of pregnancy like doctor visits and baby showers, but also protect the unborn child from those who might want to use its power for evil.
Stiles could be a major supporting character. He would be there for Scott, giving him advice on how to be a good father. He might also crack some jokes to lighten the mood during tense times. Another could be Malia. She could help Lydia with her pregnancy cravings or just be a good friend to talk to.
Adventure is also a prevalent theme. They could be exploring a new land, a mysterious dungeon, or a far - off planet. This allows for a lot of exciting scenarios and character development. In an adventure - themed fanfic, they might face dangerous creatures or solve complex puzzles, all while growing closer as characters.
It could be her long - time boyfriend. They might have been planning for a family in the future, but the pregnancy comes as a bit of a surprise earlier than expected.
The main characters are Alex and Aiden, of course. Alex might be depicted as the more adventurous one, always ready to jump into new situations, while Aiden could be the more cautious, thinking things through carefully.
Not having detailed knowledge of the 'aiden animations story', we can only guess. Aiden must be a main character. There could be a group of friends around him. For instance, a brave and adventurous girl who is always ready for action, and a nerdy boy who has a lot of knowledge and uses it to help Aiden in tricky situations. There may also be a mysterious character who appears from time to time and has some hidden connection to Aiden or the overall story arc.
The pregnancy in the Emily and Aiden fanfiction could bring out different sides of their characters. Emily, who has been so focused on revenge, might start to show a more nurturing side. Aiden could become even more protective. There could be a lot of drama as they try to keep the pregnancy a secret from their enemies. They may need to make sacrifices in their revenge plans to ensure the safety of the baby. For example, they might have to postpone certain operations or take less risky actions.
A new, unknown supernatural entity that feeds on the energy of unborn children with special powers. It senses the unique nature of Lydia and Parrish's baby and starts to haunt them. It causes all kinds of problems like making Lydia sick, or creating nightmares for Parrish, all in an attempt to get closer to the baby so it can feed on its energy.
The main characters are clearly Aiden, who is an alpha, and Sienna.
Edgar and Lydia are the central figures. They are probably going to be the ones driving the plot forward. Since it's a fanfiction about them being forced into something, most of the events will likely involve them in some way, whether it's their reactions to the forced situation or how they try to get out of it.