The Frankenstein monster gains dominance in the story through a combination of factors. His physical strength is one aspect, as it enables him to be a force to be reckoned with. But also, his ability to adapt is crucial. He adapts to different environments and situations, which gives him an advantage. Moreover, the fear he instills in others is a form of power. People are afraid of him, and this fear allows him to have a certain level of control and dominance. As the story progresses, these elements work together to make him a dominant figure in the narrative.
The monster gains dominance by using his intelligence. Despite being a creation, he is able to learn quickly. He observes human behavior and uses this knowledge to his advantage. For example, he learns how to manipulate people's emotions and uses this skill to get what he wants, which helps him gain dominance in certain situations in the story.