Who could be the main antagonists in a 'yuno and yuki married fanfiction'?

Well, it could be a story where Yuno and Yuki's married life is filled with adventures. Maybe they decide to travel the world together. They visit different countries, experience new cultures, and in the process, their relationship deepens. Along the way, they meet interesting people and have to overcome various obstacles as a couple, which makes their bond even stronger.

The priesthood of an ancient Egyptian cult that has been forgotten but still has some lingering power could be antagonists. They believe that the union of Sadie and Anubis is against the old ways and will bring bad luck or some sort of cataclysm. They might use dark magic to try and separate Sadie and Anubis. Also, there could be a jealous god or goddess, perhaps Isis, who is used to being in a position of power and influence. She might see Sadie as a threat to her status, especially if Sadie's relationship with Anubis gives her some sort of special powers or influence in the divine realm.

Another option could be a business rival if they are involved in a business in the fanfiction. This rival might try to steal their ideas, undermine their reputation in the market, or even try to break up their marriage in order to gain an advantage over them in the business world.

The Black Organization could still be a major antagonist. Even though Shinichi and Ran are married, the Organization might try to target Shinichi because of his knowledge of their secrets. They could try to use Ran as a way to get to Shinichi, which would create a lot of tension in the story.

I'm not sure specifically if there is a 'yuki x yuno pregnant fanfiction' out there. Fanfiction can cover a vast range of themes and pairings, but it depends on the popularity of the characters 'yuki' and 'yuno' within the fanfiction community for such a specific plot to exist. You could try searching on popular fanfiction websites.

One characteristic is the exploration of their unique bond. Whether it's a friendship or something more, the fanfiction often dives into how Yuno and Yuki interact with each other. Another is the use of their distinct personalities. Yuno might be more assertive while Yuki is more gentle, and this contrast is often highlighted.

Maybe a powerful wizard or sorceress who has a grudge against Jaune Arc or the fox's kind. This antagonist could try to use magic to break up their marriage or cause trouble between them. For example, they could cast spells to make the fox lose her memory of Jaune Arc or create illusions to make Jaune Arc distrust the fox.

The main antagonists could be some old enemies of Percy or Reyna who don't want to see them happy. For example, a vengeful monster from Percy's past might try to disrupt their relationship. Maybe it's a Titan who was once defeated by Percy and wants to ruin his newfound happiness with Reyna.

Some ancient and powerful monsters could be antagonists. Since Percy is now connected to the Fates, any disruption in the natural order might attract these monsters. They could see the situation as a chance to gain power or revenge. For instance, a powerful Titan who was once imprisoned might see Percy's new status as a way to get back at the gods by attacking him.

Some pure - blood supremacist families who don't approve of their marriage could be antagonists. They might try to cause trouble for Harry and Luna, maybe by spreading false rumors or trying to undermine their work in the wizarding world.