Echidna

Echidna (エキドナ) is the Witch of Greed. After the Sanctuary was released, she transferred her soul into Lewes Meyer and renamed herself as Omega.

Appearance
Echidna is described to give others a white impression, with long snow white hair and beautiful skin. Only her intellectual looking eyes and dress are black, the two colors drawing out her beauty, and she is mentioned to be beautiful enough that anyone would be fascinated by her.

Personality
Echidna's curiosity toward the unknown and her thirst for knowledge are the two things that define her behavior. She refers to it as love, and currently directs those feelings toward Subaru, who she has taken a massive interest in due to his Returns by Death ability, to the point that she longs to become his advisor to record the many possibilities created from his ability.

Described as being black hearted, she cannot understand the feelings of others, and can be seen as a psychopath by normal standards. If it is to get ahold of more knowledge, she has no problems with employing sophistry, lying, and deceiving others. However, she interacts with ill will only toward three people in the world: Satella, Emilia, and one other person.

Trivia

 * According to the author, Echidna's birthday is January 24.
 * Echidna's name refers to 42355 Typhon I Echidna, 42355 Typhon's moon and a companion to a binary asteroid. In Greek mythology, Echidna is a monster who was the mate of Typhon.