The phrase main character energy is associated with “main characters” from stories. It describes how a person prioritizes their happiness and well-being. It comes from high confidence and self-esteem. 

When a person acts confidently and seems smart with wits, they are considered to have main character energy. This phrase is used for people who might have impressive characteristics that would make them similar to the main characters in stories. 

Example

For example, if you drive on an empty road with the windows down, listening to music at sunset, you will feel the main character’s energy.