To develop both of their characters further, you could put them in a situation where they have a disagreement. Maybe Chase wants to follow the rules strictly while Rocky thinks they need to be more flexible to save the day. Through this conflict, they can learn from each other and grow as characters.
For Chase, you could develop his character by showing his vulnerability. Maybe he has a fear of heights that he has to overcome when he and Rocky are on a mission in a tall building. Rocky can be there to support and encourage him, which would also develop their friendship.
Rocky's character could be developed by exploring his creativity more. For example, in a fanfiction, he could come up with a completely new invention to help Chase solve a mystery. This would not only show his intelligence but also how he uses it to assist his friend.
To develop Chase's character further, you could show his insecurities. Maybe he doubts his abilities during a really tough rescue mission. Skye could then be there to boost his confidence. For Skye, you could explore her fear of heights in a different way. Like she has to face an even higher peak than usual in a rescue. This would make their characters more relatable and complex.
Marshall's character can be developed further by showing his more nervous side when it comes to his feelings for Everest. For example, he might stutter or make little mistakes around her. Everest could be developed by exploring her more independent streak and how that sometimes clashes with Marshall's more impulsive nature.
Their relationship can be developed through shared challenges. For example, if they face a really tough rescue mission together, like saving a group of baby animals from a collapsing cave. During this, they learn to trust each other's instincts more. Chase might rely on Skye's flying skills and Skye might depend on Chase's tracking abilities.
One idea could be that Chase and Rocky team up to rescue a lost pet in Adventure Bay. They face various obstacles like a flooded area where Rocky uses his tools to build a makeshift raft and Chase uses his speed to navigate through rough waters.
Marshall's character can also be developed through his relationships. For instance, having a bit of a friendly rivalry with another Paw Patrol member over who can handle the most difficult medical cases. This would bring out different aspects of his personality and how he copes with competition.
Marshall can be developed by exploring his fear of getting stuck in the snow. Maybe in the fanfic, he has an incident where he almost gets buried in a snowdrift. This makes him face his fear and with Everest's help, he overcomes it. Everest, on the other hand, can be developed in terms of her patience. Since Marshall might be a bit clumsy in the snow at first, she has to be patient with him, and through this, she becomes more understanding and empathetic.
You could also explore their pasts more. Maybe there were events in their childhood that affected how they interact now. By delving into these memories, both Chase and Adam can have a better understanding of themselves and each other, leading to more complex and well - rounded characters in the fanfiction.
Another possible theme could be discovery. They could discover new things about themselves or their abilities while interacting with each other. Maybe Tundra has a hidden talent that Rocky helps bring out, or vice versa. And this discovery could lead to them becoming even better Paw Patrol members and closer friends.
Give them personal goals outside of the regular Paw Patrol missions. Maybe Skye wants to be the best flyer in the whole region and is constantly practicing new stunts. Chase could be aiming to learn a new skill like tracking rare animals. When these goals are incorporated into the story, their characters become more complex. Also, show their relationships with the other pups in more depth. How do they interact with Rubble or Zuma? This can further develop their own characters as well.
One great place to find Paw Patrol Rocky x Zuma fanfiction is on fanfiction.net. There are various stories there that explore their friendship in different ways. Some might focus on them having an adventure together where they use their unique skills to overcome challenges, like Rocky's recycling know - how and Zuma's water - based abilities.