Echidna

Echidna was known as the Witch of Greed. She was mentioned throughout the series, mainly for her relationship to Roswaal and Beatrice, but she made her formal appearance as a prominent supporting character and subsequently secondary antagonist in Arc 4. Echidna's barely-exposed skin was porcelain-like and pure white, so colorless that it appeared all color had been bleached out of her life. She was frequently spotted smiling and acting casually until the subject changed to something she was actually interested in. Because of her lovely features, she frequently gave the impression of a maiden.

Echidna's behavior was characterized by her curiosity in the unknown and hunger for knowledge. At first impression, she appeared to be pleasant, soft-spoken, understanding, and even infantile. The other Witches described her as clumsy, like the time she unintentionally set fire to the forest, nearly burning to death, while trying to warm herself. She was described as "black-hearted," unable to understand the emotions of others, and may be classified as a sociopath by normal standards.

Echidna was able to employ Greed's Authority. When she returned to the world as Omega, she most certainly lost access to her Authority of Greed. Echidna could employ all six elements and was exceptionally talented in all of them with unrivaled mastery at the time. She was capable of casting every magic known at the time, and she even invented her own. No one ever came close to her entire talent with using magic, even after her death, until Roswaal L Mathers became the first and only person to challenge and even surpass her in magical knowledge and proficiency.

Anime: Re:Zero