Akua Shuzen is the oldest sister in the Shuzen Family and the stepsister of Moka. Being Alucard's granddaughter as well, Akua seems to possess comflicting personality values. She has a deep sister complex for Inner Moka and loves her very much, but her promise to Akasha to keep Inner Moka safe prevents her from being with Outer Moka. However, she also wishes for the desturction of humanity and is willing to allow Gyokuro to use Moka to awaken Alucard. The reason she became a member of the Shuzen family was to try and steal the power of Akasha Bloodriver, one of the strongest vampires in existence and the sealer of Alucard, an ancient vampire who once aspired to destroy the world. Akua's mother died when she was young, and she had lived with a relative in China prior to living with the Shuzen family (explaining why she often speaks Chinese).
It is also shown Akua is extremely skilled in Chinese kung-fu, as her Yōho Saishusui ("Twist Step, Plucking Hand Strike") would knock a person out for at least three days.[60] In addition, she has also mastered the Hōgetsu Jigen-Tō ("Moon-Crushing Dimensional Sword"), a technique used by Tohofuhai, and her skill at the technique is superior to that of Tohofuhai's apprentice Ling-Ling Wong, allowing Akua to use the technique defensively as well as offensively by rendering her body intangible. Akua has amazing insight in battle, as she was able to see the truth behind Kalua's "tears". It has been noted by Tohofuhai that her body has not aged at all ever since he first saw her in Moka's flashback, suggesting she is immortal.[59] She is known to the Chinese mob scene even as a child, and is called the Black Devil because of her black clothes and lethal kung-fu; even Moka was in awe when Akua saves her from Chinese mobsters in her introductory chapter. Akua's name is perhaps a pun on "aqua", the Latin word for water.