Faery Tales & Nightmares

The stories range from whimsical to darker themes, and I'm curious about the selection process and whether any stories were inspired by traditional folklore.

Some tales had a haunting quality that made me think about the fine line between enchantment and danger in fairy lore. How did others interpret these nightmares versus the more whimsical stories?

The romantic elements felt natural but also added emotional depth. Was this a conscious choice to modernize classic themes or to appeal to young adult readers?