Rick Riordan said this quote

Hades raised an eyebrow. When he sat forward in his throne, shadowy faces appeared in the folds of his black robes, faces of torment,as if the garment was stitched of trapped souls from the Fields of Punishment, trying to get out. The ADHD part of me wondered, off-task, whether the rest of his clothes were made the same way. What horrible things would you have to do in your life to get woven into Hades' underwear?