The living Aizen Myōō appeared to me in the glow of the sunset on New Year’s Day. I have become the twenty-third successor to the dharma transmitted from the Great Sun Buddha.

Twenty-fifth day of the sixth month in the sixth year of Kenchō (1254)

Nichiren presents this to the New Buddha.

The living Fudō Myōō also appeared to me in the light of the full moon from the 15th through the 17th day of the same month. I have become the twenty-third successor to the dharma transmitted from the Great Sun Buddha.

Twenty-fifth day of the sixth month of the sixth year of Kenchō (1254)

Nichiren presents this to the New Buddha

Fudō Aizen Kanken-ki, Record of Seeing Fudō and Aizen Myōō, Writings of Nichiren Shōnin, Biography and Disciples, Volume 5, Pages 1

I’ve included this letter from 1254 as an example of why Nichiren writes 24 years later in 1278, “Now, as far as my theology goes, I would like you to think that what I have expressed before being banished to Sado Island can be equated with the forty or so years in which Śākyamuni had taught before revealing the Lotus Sūtra (that is, the truth and true aims of the Buddha were not directly divulged in those years).” Misawa-shō, A Letter to Lord Misawa of Suruga, Writings of Nichiren Shōnin, Doctrine 2, Page 241. I will be pointing back to this when I get to the letters criticizing Kamakura Era trends in Mikkyo thought.

Needless to say, this event had a lasting impact. As the Introduction to this letter states:

The impact on Nichiren from this experience of seeing Aizen and Fudö was such that he would always inscribe Sanskrit characters representing the two divine protectors of Buddhism (seed-letters) when drawing his Mandala.

Lotus World has this to say about Aizen Myōō (Ragaraja Vidyaraja):

These esoteric deities are the kings of mystic knowledge who represent the power of the buddhas to vanquish blind craving. They are known as “kings of mystic knowledge” because they wield the mantras, mystical spells made up of Sanskrit syllables imbued with the power to protect practitioners of the Dharma from all harm and evil influences. The Vidyarajas appear in terrifying wrathful forms because they embody the indomitable energy of compassion that breaks down all obstacles to wisdom and liberation.

Achalanatha and Ragaraja are represented on the Great Mandala by the respective bijas, or “seed syllables,” that embody their essence. In this case, the seed syllables are written in Siddham, a variant of Sanskrit. They are the only parts of the Great Mandala written in the form of Sanskrit bijas.

Ragaraja Vidyaraja is the king of mystic knowledge who reigns over the passions of love and erotic desire. He is very popular in Japan with geisha, artisans, and those who are concerned with love and sensual desire. Like Achalanatha, Ragaraja Vidyaraja is a wrathful manifestation of Mahavairochana Buddha. He overcomes passion not by suppressing it but by transforming it into the compassionate aspiration to liberate all beings. Ragaraja Vidyaraja has three eyes with which he sees the realms of desire, form, and formlessness. Like Achalanatha, he is surrounded by flames that burn away karmic hindrances. His many arms represent his multitude of powers and capabilities; in them he carries such traditional Buddhist symbols as the lotus flower and vajra. Like the deity of desire known as Kama, he also bears a bow and arrow, but in this case they represent the power of concentration and penetrating insight.

Lotus World has this to say about Fudō Myōō (Acalanatha Vidyaraja):

Achalanatha Vidyaraja is the chief of the five kings of mystic knowledge in esoteric Buddhism. He is very popular in Japan as a destroyer of demons, black magic, sickness; and all forms of evil. He is also revered in Japan as the protector of the nation . According to some interpretations he represents the transmutation of the sufferings of birth and death into the bliss of nirvana.

Achalanatha Vidyaraja is considered a wrathful form or manifestation of Mahavairochana Buddha, who personifies the Dharma-body or Truth-body of the Buddha. He is shown surrounded by flames that consume all karmic obstacles. His sword of wisdom cuts through greed, anger, and ignorance. He uses his lasso to bind the forces of evil but also to catch and draw near those in need of self-control and discipline. The rock he sits on represents his overcoming of the hindrances to enlightenment but also his immovable determination to liberate all beings.

100 Days of Study