Majora's Mask and Twilight Princess often receive the unique honor of being crowned the darkest games in the Zelda series, and understandably so. Aside from containing some of the most jarring visuals in the series, both of those games contain gameplay and story elements that are often violent, and sometimes downright scary. However, being "dark" isn’t just about maturer-looking character designs or doomsday plot elements. Sometimes, the true darkness lies in the themes explored in a narrative, and what they tell an audience about its characters.
Source：https://www.cbr.com/ocarina-of-time-is-the-darkest-zelda-game/
