The founder of the Harpy Village lived hundreds of years ago, Delphine was called "The Soulkeeper". She had the ability to communicate with people's souls through an archaic ritual, a kind of ancestor of oracle magic mixed with potions. Some say she was also able to speak with the spirit of the Titan.
It's from her that Chief Juno's necklace takes its name, the Key of Delphine is an artifact that harpy chiefs have given from hand to hand for many years. It has the ability of opening and closing everything.

The Owl House belongs to Disney
Delphine belongs to me