The Niō (仁王, lit. Two kings) are two wrath-filled and muscular guardians of the Buddha, standing today at the entrance of many Buddhist temples in Japan under the appearance of frightening wrestler-like statues.
The Diamond-rod wielding Shukongōshin (Agyo), Asakusa Temple, Japan.
The wrestler Kongo Rikishi (Ungyo) in Nikko, Japan
One of the protectors, Agyo (阿形) or Shukongōshin, is a symbol of overt violence: he wields a thunderbolt stick and bares his teeth.
The other, Ungyo (うん形) or Kongo Rikishi, is either bare handed or wields a sword and symbolizes latent strength, holding his mouth tightly shut.
Both are manifestations of the BodhisattvaVajrapani, protector deity of the Buddha.
The Nio Protectors are part of the Mahayanapantheon and as such were probably influenced by the Greco-Buddhist interaction of Buddhism with the Hellenistic culture of Central Asia from the 4th century B.C. to the 4th century A.D. Together with the Herculean expression of Vajrapani in Mahayana Buddhism, their attributes, physical qualities and attitudes seem to get their inspiration from those of the Greek god Heracles.
The Nio (Benevolent Kings) are a pair of protectors who stand guard outside the temple gate at most Japanese Buddhist temples, one on either side of the entrance.
At some Buddhist temples, the Nio guardians are replaced with a pair of mythical and magical Shishi Lion-Dogs -- one with mouth open, the other closed.
Vajrapani is common to all Schools of Tibetan Buddhism and has numerous forms and practices which span all sets of tantric classification and levels of complexity from a solitary aspect up to the large and complex mandalas with many deities.
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