One plot twist could be that Sharkboy turns out to be from a future where Lavagirl has become an evil dictator. He travels back in time to stop her from turning bad. This completely flips their relationship dynamic and adds a whole new layer of complexity to the story.
A plot twist might be that Lavagirl's lava powers are actually a curse put on her by an ancient sorcerer. Sharkboy has to find a way to break the curse without killing her. This would change the nature of her powers from being just a cool superpower to something that is a source of pain and danger for her.
Perhaps Sharkboy and Lavagirl discover that they are actually siblings separated at birth. This revelation would shock them both and force them to re - evaluate their relationship. They would have to deal with new emotions and also figure out how their powers are related in this new context, which could lead to a very different kind of adventure for them.
Perhaps they could go on a journey to a new magical world where they discover new aspects of their relationship. In this world, they might have to prove their love in different ways, like solving puzzles together.
An interesting plot could be an OC who is a tech - genius and creates new gadgets for Sharkboy and Lavagirl. For example, a device that can enhance their powers or help them travel faster. The OC could also have a personal vendetta against a villain who is using technology to disrupt the balance in their world. This would lead to a story where the OC, Sharkboy, and Lavagirl team up to defeat the high - tech bad guy. It could involve a lot of action - packed scenes in a high - tech city or a secret lair.
One idea could be that Sharkboy and Lavagirl find themselves in a new dimension where they meet characters from another story. They have to team up with these new characters to defeat a common enemy that threatens both their worlds. For example, they might encounter a powerful ice - themed villain who is freezing over all the water in their world and the new world they've entered. Sharkboy's ability to control water and Lavagirl's heat - based powers would be put to the test as they try to stop this villain.
One idea could be exploring their adventures in a new dimension where they have to face a powerful enemy together. Their relationship could deepen as they rely on each other's unique powers.
Another idea is a story where Sharkboy and Lavagirl go on a journey to discover the origin of their powers. They might encounter some ancient guardians or face challenges that test their friendship and make them grow stronger as they learn more about themselves and their abilities.
The kiss in the fanfiction also serves as a plot - driving element. It can change the course of their story. For example, it could be the turning point where they decide to face their enemies together more united than ever, or it could be a moment of realization for their true feelings that then leads to further character development.
The kiss is special because it represents the union of their powers in a way. Their relationship is not just about romance, but also about how they complement each other. The kiss can be seen as a physical manifestation of that harmony between them.
One common theme could be the power of their love overcoming challenges. Since they both have unique powers, there might be stories where their love helps them face external threats.
First, think about the setting. You could start with them in their normal world, like in the movie, and then introduce a new situation that sets the stage for their love story to develop further.
I'm not sure about specific "sharkboy and lavagirl love fanfiction" but you can try searching on fanfiction websites like Archive of Our Own or FanFiction.net. There might be some interesting stories created by fans there.