Well, a popular plot twist is when Serena goes missing during her pregnancy. Ash then has to go on a journey to find her, all while dealing with his own fears and insecurities about becoming a father. It adds a lot of drama and adventure to the fanfiction. Also, there could be a plot twist where the baby has some kind of unique ability that no one expected, like being able to understand the language of legendary Pokémon right from birth. This then leads to all kinds of new adventures and challenges for Ash and Serena.
In some of these fanfictions, a plot twist could be that the pregnancy is not as straightforward as it seems. Maybe there are some magical or scientific elements involved. For example, the baby might be the result of a special experiment gone wrong (but in a good way in the context of the story). Or perhaps there's a time - travel related plot twist where the pregnancy is somehow connected to events in the past or future of the Pokémon world. This can make the story really exciting and full of mystery.
One common plot twist could be that Ash is initially in denial about Serena being pregnant. He might think it's some kind of mistake or a plot by an enemy at first. Another could be that Serena discovers she has some special powers related to the pregnancy that are connected to the Pokémon world, like being able to communicate with a certain type of Pokémon better. And sometimes, there could be a plot twist where they find out the pregnancy is part of a prophecy that will change the entire Pokémon universe.
I'm not sure about specific popular ones as this is a rather unusual and not very family - friendly concept in the context of the Pokémon series. Fanfictions often vary greatly in quality and content, and this particular theme might not be widely promoted in mainstream fanfiction communities.
One possible plot development could be that Ash and Serena have to deal with the new responsibilities of having a baby. This might cause some tension between them as they figure out how to balance their own goals and the needs of the family. Lemon could be involved as a support system, or perhaps as a source of conflict if there are romantic feelings involved among the three. For example, if Lemon has feelings for Ash, Serena's pregnancy could make those feelings more complicated.
In fanfiction, anything can happen. However, without specific details of the particular fanfic, it's hard to say for sure if Serena is pregnant. Some fanfictions might explore this plotline for the sake of drama or character development. It could add an interesting twist to the relationship between Ash, Serena and Lemon, but it also depends on the overall theme and direction the author wants to take the story.
A great plot twist could be that one of their Pokémon turns out to be a legendary in disguise. For example, Serena's Fennekin could be revealed as a Zoroark that was sent to protect her, but she had no idea all along. This would completely change the dynamic of their journey.
In some fanfictions, the plot could center around Ash and Serena's reactions to the pregnancy. Ash might be over the moon with excitement, while Serena could be a bit more nervous about becoming a mother. They could also have different ideas about how to raise the child. For example, Ash might want the child to be a Pokémon trainer from a young age, while Serena could be more focused on giving the child a normal childhood first. Also, the pregnancy could bring out a more protective side in Ash towards Serena, making their relationship even stronger.
One common storyline could be about their journey together as they prepare for the baby. It might include Ash being overly protective and Serena having to deal with her changing body and new emotions. Another could be a story set in a different Pokémon region where they face unique challenges as expectant parents, like dealing with new Pokémon species that are helpful or harmful during pregnancy.
Some Serena x Ash fanfictions are centered around Serena's feelings for Ash. These stories often explore how she first realizes her love for him and how she tries to express it. Maybe she decides to cook his favorite meal as a way to show her affection, or she gives him a special Pokémon - themed gift. In other fanfictions, Ash might be the one who starts to notice Serena in a different light. He could see how she has grown stronger and more confident, and this new - found admiration could turn into something more romantic. There are also those fanfictions that bring in other Pokémon characters to either help or hinder their relationship.
There's a fanfiction where Ash, Serena, and a group of other characters form an interesting dynamic in a harem - like setting. In this story, they travel through different regions, and Serena plays a key role in Ash's journey, not just as a love interest but also as a strong ally. It delves deep into their relationships and how they grow together. This type of fanfiction allows for a lot of creativity in exploring different aspects of the Pokémon world and the characters' personalities. For example, it might show how Serena's cooking skills are not only useful for the group but also a way to bond with Ash and the others in the harem - like group.
One popular Ash and Serena love fanfiction could be 'A Journey of Love'. In it, they might go on adventures that strengthen their bond beyond what we see in the original series. Another could be 'Serena's True Feelings', which might focus on Serena's perspective of her love for Ash and how she overcomes various obstacles to be with him. There are also fanfictions that rewrite the entire journey with a strong focus on their relationship development from the very start.
One popular plot twist is when an old enemy returns to try and break up their marriage. It adds drama and conflict to the story. Another is when they discover a rare Pokemon that has the power to change their relationship in some unexpected way.