Aizen Myouou (アイゼンミョウオウ, Aizen Myōō)?, also known as Ragaraja (ラーガラジャ, Rāgaraja)?, is a demon in the series.
Aizen Myouou is considered a Vidyaraja or "Great Wisdom King", in keeping with others like Fudou Myouou and Gozanze. There are four different mandalas associated with Aizen Myouou. The first posits him with thirty-seven assistant devas, the second with seventeen.
He is portrayed as a red-skinned, frowning man, his appearance representing suppressed lust and passion. He variously has two, four or six arms; in the latter form, his hands bear a bell, a stick, a thunderbolt, a lotus, a bow and an arrow. Similarly, he sometimes has two heads, with a lion's head in his wild hair. According to the Yogin Sutra attributed to Vajrabodhi, he represents the state at which sexual excitement or agitation becomes enlightenment and passionate love becomes compassion for all living things.
Aizen Myouou serves as Kei Nanjo's initial Persona. It is awakened when Kei's butler Yamaoka died in front of him. This Persona is actually the second Persona of the Hierophant Arcana and can be created again utilizing gems in the Velvet Room. Aizen Myouou has balanced stat increases as it ranks up and upon being returned to the Velvet Room at MAX Rank, yields a Vitality Incense.