Who could be the main antagonist in a 'Steven Universe Past Meets Future Fanfiction'?

It could be a new villain from the future that somehow follows future Gohan back in time. This villain might be an evolved form of an existing enemy, stronger and more cunning. They could be after the secrets that future Gohan holds about the future technology or the power levels of the Z - fighters in the future.

A group of Homeworld Gems who believe that Black Pearl has become too 'contaminated' by her interactions with the Crystal Gems and Steven. They see her as a threat to the traditional Gem order and send a special task force to capture or destroy her, which would make them the main antagonists as they try to stop Black Pearl from living her new life.

Perhaps past versions of the Crystal Gems meet their future selves. They could be shocked by how much they've changed, or they might learn valuable lessons from each other. The past Gems could see how their actions in the past led to the future they now inhabit, which could be a really interesting exploration of cause and effect.

It could be another gem who doesn't want Steven and White Diamond to form an alliance. Maybe a rogue gem who fears that their combined power would disrupt the current power balance in the gem universe.

If it was a crossover with "She - Ra and the Princesses of Power", Adora could be a main character. Her strong leadership and the power of She - Ra would be an interesting contrast to Steven's more laid - back leadership style. Together, they could fight against a common enemy that threatens both their worlds.

It could be a corrupted Gem that has the ability to disrupt Steven's new ways of sensing the world. This Gem might be able to create illusions that confuse Steven's other senses, making it difficult for him to rely on his friends or his new powers.

It could be a time - traveling enemy from the future who wants to stop Naruto from changing things. This antagonist might have his own motives for wanting the future to remain as it was, like having power over a ruined Konoha.

Perhaps there is no traditional antagonist. Instead, the conflict could be within Percy himself. His future self might have some dark secrets or regrets that Percy in the present doesn't want to face. So, in a sense, Percy's own denial or fear could be the 'antagonist' in this fanfiction.

In 'Steven Universe Watch the Future fanfiction', Steven is bound to be a central figure. He's the protagonist of the original series, after all. Alongside him, the Crystal Gems - Garnet, Amethyst, and Pearl - are very likely to be main characters. They've been with Steven through thick and thin. Additionally, characters like Peridot, Lapis Lazuli, and Bismuth, who have become important parts of Steven's life in the later parts of the series, could also be main characters. Connie, with her connection to Steven and her own growth in the story, is also a strong candidate for a main character.

Perhaps Nico's own insecurities could act as an antagonist. His future self might be so different and successful that Nico starts to feel inadequate and his self - doubt tries to prevent him from fully interacting with his future self and learning from the encounter. Another idea is that there could be a group or organization in the story that has rules against time - traveling encounters like this, and they try to stop Nico from having this meeting.