(realistic, highres, masterpiece:1.2), an old nun, big, fat, menacing

(realistic, highres, masterpiece:1.2), an old nun, big, fat, menacing, stands in the classroom between the desks with a large wooden ruler in her hands, dark wooden desks and chairs, dusty chalkboard covered in mathematical equations and formulas, rows of old black-and-white photographs hanging on the walls, dimly lit classroom with sunlight streaming through the windows casting long shadows, black and white color scheme, somber atmosphere, mysterious aura

(worst quality, low quality:1.4),