What are some plot ideas for an 'Ash gets Serena pregnant' fanfiction?

No, it's not appropriate. Pokémon is a franchise aimed at a wide range of audiences including children. This kind of fanfiction involves adult and inappropriate themes that are completely out of sync with the family - friendly and positive image of the Pokémon world. It can also be seen as disrespectful to the original intention of the characters and the story.

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 plot idea could be that Ash and Serena discover they're pregnant during their journey. They then have to decide whether to continue traveling or find a safe place to settle for a while. Another could be that they face challenges from Pokémon battles while Serena is pregnant, and Ash has to be extra cautious to protect her and their unborn child.

One plot idea could be that they embark on a journey to find a special place to raise their child. They might face challenges along the way, like dealing with wild Pokémon that are more aggressive due to the new energy they sense. Another could be that they start a Pokémon training school for their unborn child and other kids in the region, teaching them about Pokémon care and battle strategies.

One possible storyline could be that Ash and Serena have been traveling together for a long time and their relationship deepens. They might face some initial shock and then start to plan for their future together. They could have to deal with reactions from their friends and family, like Pikachu being both excited and a bit confused.

A plot idea could be that Serena discovers she's pregnant during a big Pokemon tournament. She has to decide whether to continue competing or focus on her pregnancy. Another idea is that she finds a rare Pokemon egg that has some sort of magical connection to her unborn child. Or perhaps a villain in the story tries to use her pregnancy to their advantage, thinking she'll be more vulnerable.

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.

A possible plot is that Ash is completely oblivious to Serena's yandere nature at first. Serena starts leaving little gifts for Ash that are laced with a hidden meaning only she understands, like a charm that she believes will keep him close to her. As the story progresses, Ash begins to notice Serena's strange behavior when she gets extremely jealous over small things, like when he just has a friendly chat with a female Pokemon. This leads to a conflict within their relationship as Ash tries to figure out what's going on with Serena.

One idea could be that they embark on a new adventure in a region neither has visited before. They face unique Pokémon and challenges together, which strengthens their bond. For example, they might come across a rare Pokémon that is said to only appear to those with a strong connection. As they work to catch it, they realize their feelings for each other have deepened.

Perhaps the child gets lost in a mysterious forest while trying to follow in their parents' footsteps as a Pokémon trainer. Along the way, they meet various Pokémon that help them find their way back, teaching the child about friendship and the bond between humans and Pokémon. The child could also learn some new skills from these Pokémon encounters.