Characters are the most important, in my opinion.
The majority of sets within the theme are characters, as opposed to locations, vehicles, creatures, or accessories.
The world building is an important aspect of any story, and a filled-in world is able to provide resources or setting for events, and can change as a result of actions, which characters influence and take experience from.
The stories have always been character centered, and all events are made in reference by one or another, even an unseen personification.
The characters are integral to how the stories are initiated, experienced, and resolved, and are easier to get attached to as vectors for both world building and plot, and who can be made by an audience seeing and handling the sets.
My point stems both from being a writer myself, and also as a fan who never saw much of the deeper lore for Bionicle G1 until around 2015. Characters were imagined largely based on limited knowledge drawn from promotional material or the appearance of a model, and filled in independently.
Looking back at 2001 I chose characters
I think it’s a balance between atmosphere and character. We can view the world as islands, biomes, planets etc, but really the world our characters navigate is the social one they’re a part of. That social atmosphere is a direct result of the characters that it’s made up of, and in turn, it shapes the next generation of characters, who then restructure the social world, and the cycle repeats. Our characters are simply navigating an atmosphere crafted by the characters that came before, and that thread can be chased backward and forward well beyond the scope of the story we have access to. I don’t think it can be either one, I think it has to be both simultaneously.
But if I had to pick one, I’d drop any reasoning and say world-building and atmosphere because that’s the most fun for me.
