I believe that it is idiom because that is a commonly used expression
        
             
        
        
        
 Myths are stories that are written by unknown authors. The purpose of these stories is often to explain complex concepts before science or proof could explain them. They are also used to teach people morals. Myths may often be religious or attempt to explain how the world came to be.
        
             
        
        
        
Answer:
She opposes the protagonist.
Explanation:
Antagonists always oppose the protagonist.
Think of it as a villian versus a hero or a main character vs conflict.
 
        
             
        
        
        
Subordinate clause, a complete sentence, a compound subject, a main clause