Echidna

Echidna is one of the legendary Witches of Sin, carrying the title of the Witch of Greed. Unlike most witches who are feared for cruelty, Echidna's defining trait is an endless hunger for knowledge. She is endlessly curious about the world and willing to lie, trick, or manipulate anyone if it helps her learn something new.

Because she struggles to understand other people's feelings, many who meet her consider her cold or even heartless. She does not act out of malice so much as plain curiosity, which makes her unpredictable and hard to trust. When she learns about Subaru Natsuki's strange power to return from death and try again, she becomes fascinated and offers herself as his advisor so she can study the ability up close.

Echidna is also tied to the story's past through Roswaal, the eccentric noble who once loved her deeply and has spent years trying to bring her back from death. Her connection to figures like Satella and Emilia is colored by old resentments from her life as a witch, adding another layer to the tangled history between the witches and the present-day cast.