Final answer:
In 'The Yellow Wallpaper', the character with the most power is the husband, John.
Step-by-step explanation:
In 'The Yellow Wallpaper' by Charlotte Perkins Gilman, the character with the most power is the husband, John. Throughout the story, John exercises control and domination over the protagonist, his wife. He restricts her activities, dismisses her concerns, and denies her agency, which ultimately contributes to her decline into mental illness.