Can the manticore bite through steel? Does the dragon’s fire melt stone? What happens when someone gets hit with those mage fireballs? Any piece of fiction that has fantastical, sci-fi, superhero, or any variation of those elements needs to have consistent internal logic. It’s the thing that keeps us, the audience, rooted in the world even though Strongman is swinging a bus like a baseball bat. 

A lot of worldbuilding happens on the backstage of the story. The amount that is actually shown to the audience is usually pretty minimal. Maybe that’s the most effective way of communicating aspects of the world. To let there be some mystery, some questions that the reader has to answer themselves. 

That means what they imagine compared to what you imagine won’t always be the same, but that’s okay. It’s for the better.