Who had the saddest story in one piece?

In "One Piece," Nico Robin has one of the saddest backstories. As a child, she was the only Survivor of the Ohara incident, where the World Government destroyed her home and family due to her research into the Void Century. She spent years on the run, isolated and hunted for her ability to read the Poneglyphs, longing for acceptance and belonging. Her tragic past and struggles for survival evoke deep empathy from fans, making her story one of the most poignant in the series.