 The two skulls speak alternately (the top skull speaks with a deep voice, whereas the bottom one speaks with a childlike voice), often finishing each other's sentences, and refer to themselves as "we", suggesting that Aaroniero is, to some degree, two separate beings.Aaroniero is introduced as one of the last first-generation Espadas as well as the only Gillian member of the current Espadas.But in spite of being a Gillian, Aaroniero is made an Espada due to his unique talent of devouring other hollows through his tendril-like "Zanpakutō", , a deformed mouthed appendage in place of his left arm which he usually covers with his robes and a glove.