One interesting interaction could be between Percy and Tony Stark. Percy, being used to a more mythological world, might be fascinated by Stark's high - tech gadgets. Stark, on the other hand, could be intrigued by Percy's ability to control water. They might start off bickering about whose powers are better but then end up respecting each other.
A great character interaction would be between Natasha Romanoff and Annabeth Chase. Natasha's spy skills and Annabeth's strategic mind could lead to some really intense conversations. They could be planning how to outwit the villains together. Natasha might teach Annabeth some hand - to - hand combat skills, while Annabeth could share her knowledge of ancient strategies that could be useful in the Civil War situation.
I think the interaction between Hulk and Grover would be fascinating. Grover is this gentle, nature - loving satyr, and Hulk is, well, the big green rage - monster. Grover could try to use his empathy and nature powers to soothe the Hulk, which could lead to some really comical and heartwarming moments. Also, Natasha Romanoff and Clarisse would be an interesting duo. Natasha's stealth and combat skills combined with Clarisse's brute force and no - nonsense attitude could make for some great fight scenes and character development.
Another interesting interaction would be between Annabeth and Tony Stark. Annabeth is highly intelligent and strategic, much like Tony. They could either be in a battle of wits, constantly trying to one - up each other in terms of coming up with plans, or they could end up working together really well. Annabeth could teach Tony about ancient Greek architecture and strategy, while Tony could show her some of his latest high - tech inventions.
One way the worlds could collide is through a magical accident. Maybe some of the Infinity Stones' power messes with the magic in Percy Jackson's world, causing portals to open. Percy and his friends could be sucked into the Avengers' universe right in the middle of the Civil War. They might side with different factions based on their own beliefs about power and control.
Percy Jackson himself is always interesting. His courage and ability to face the gods head - on make him stand out. Another could be Annabeth. Her intelligence is a great asset in the chaos of the civil war. She can strategize and come up with plans to help Percy. Also, some of the more minor god characters that are given more depth in the fanfiction can be really interesting. For example, a lesser - known god who has a unique power and a strong motivation in the civil war.
Another plotline could be Spiderman's relationships with other characters during the Civil War. He might form a closer bond with Captain America as he begins to understand Cap's perspective on the Sokovia Accords. Or perhaps he has a falling out with a fellow Avenger who doesn't agree with his stance. This could lead to some intense emotional moments and character development for Spiderman.
One interesting crossover could be the powers of the demigods in Percy Jackson combined with the high - tech abilities of the Avengers. For example, Percy's water - controlling powers could be used to put out fires during an Avengers - level battle in a city. Or Annabeth's strategic mind could help the Avengers plan better attacks against a common enemy.
Another plot could focus on individual characters' struggles post - Civil War. Like how Tony Stark tries to make amends with those he fought against while still dealing with his own guilt. Maybe he starts a project to help the victims of the Sokovia incident which was a big part of the rift between the Avengers.
One common plotline is the Avengers reacting to alternate versions of the Civil War events. For example, they might see a version where more heroes died during the battle. Another is them getting to interact with the characters from the Civil War in a different setting, like a post - apocalyptic world where the events of Civil War led to total chaos.
I really like the idea of Percy and Magnus just chatting about their lives. Percy talking about his experiences with the Greek gods and Magnus sharing his Norse - related adventures. It would be a simple but really engaging interaction.
A great crossover would be Percy teaming up with Thor. Since Thor has his lightning powers and Percy has his demigod powers, they could combine their forces in a really cool way. Maybe Percy could use the water to conduct Thor's lightning, creating a powerful and unique attack. Also, Percy's knowledge of Greek mythology might give the Avengers some new insights into dealing with otherworldly threats.