Black Altar Avido (暗黒祭壇星座（ブラックアルター）のアヴィド, Burakku Arutā no Avido) is the Black Altar Saint as well as the leader of the Nero organization, and former apprentice of Altar Hakurei.
Initially, Avido was an apprentice of Hakurei, who taught him the Praesepe combat technique, which he mastered. However, Hakurei learned that Avido surrendered to greed, and drove him out of the Sanctuary.
Avido then became a Black Saint and formed a criminal organization called Nero, a XVII Century mafia centered in Venice, with the objective to rule the world and destroy the Sanctuary. He still bears a grudge against his former master and believes the Sanctuary to be unworthy of ruling the world, as they are devoid of desires. He has mastered the Praesepe combat technique, commonly associated with the Cancer Gold Saint, as proven by his usage of the Praesepe Demonic Blue Flames on Lumaca's spirit, he also is able to use the technique to destroy not only the body but also the soul of his victim.
- Sekishiki Meikai Ha (積尸気冥界波):
- Sekishiki Kisōen (積尸気鬼蒼焔):
- Sekishiki Konsō Ha (積尸気魂葬破):
Altar, is a southern constellation lying between Scorpius and Triangulum Australe. It is one of the 48 constellations listed by Ptolemy in the second century and one of the 88 existing constellations.
Ara contains no bright stars, Beta Arae being the most prominent of magnitude 2.85. However, probably more relevant the stars Mu Arae star with four known planets, and Gliese 674, a red dwarf planet in an orbit very close to the star. Among the deep sky objects must stress the Cluster Westerlund 1 or Ara, the most massive compact star cluster in the Local Group. Situated at a distance of 5 kiloparsecs (~ 16,000 light-years), age is estimated between 3.5 and 5 million years.