Ring of Gaea

The Cult of Gaia (known as the Deva Cult in Megami Tensei II) is a recurring cult which appears in the Shin Megami Tensei series. The Cult of Gaia are commonly associated with occult activities, and generally embody the Chaos alignment.

Gaians typically believe in free will, and that the strong should be the ones to rule. This commonly puts them at odds with the Order of Messiah, who are associated with the Law alignment.

Shin Megami Tensei
Before the ICBM barrage caused by Thor, Gotou, who was himself an avid follower of the cult, led Japan under martial law and led the Gaians using the aid of demons. Later on, Chaos Hero joins the Gaians with his partner Rie after fusing with a demon at the Jakyou Manor.

During the section of the story concerning Tokyo Destiny Land and the Shingawa, Echidna represents the Gaians and the Chaos alignment in Tokyo Destiny Land, while Haniel in Shinagawa represents the Messians and the Law alignment. If you kill Haniel and then choose to help the Gaians, you will be locked into the Chaos alignment. If you kill both Echidna and Haniel, you end up in the Neutral path, and if you kill Echidna and then choose to help the Messians, you will be locked into the Law alignment.

Helping the Gaians take over the Great Cathedral are four demons; Surt, Astaroth, Arioch, and Asura.

Shin Megami Tensei II
The cult makes fewer appearances in the sequel. On the way to Virocana however, you can find the soul of a member of the cult in a room and he will tell you that he was caught by the Messiah Church worshipping another deity and was executed.

Shin Megami Tensei III: Nocturne
The Gaian Cult is mentioned early in Shin Megami Tensei III: Nocturne. Prior to the Protagonist(Hito-Shura)'s transformation into the Demi-Fiend, he encounters Jyoji Hijiri, who gives him an occult magazine related to the cult.

Later, Chiaki reveals the the Cult of Gaia is responsible for the murder incidents, and that Shinjuku Medical Hospital is the homebase of the Cult, via information from the occult magazine.

When the Conception occurs, the Hospital is the only place not affected by the destruction. In the updated re-release of Nocturne, Shin Megami Tensei III: Nocturne Maniax, it is revealed in the Amala Labyrinth that Hikawa was once a member of the Gaia Cult.

Hikawa eventually betrayed the cult after he obtained the Miroku Scripture. He then began his plans to destroy the cult with the Conception and establish his own Reason of Shijima to recreate the world to his liking.

Several Gaians and Messians alike were murdered by demons summoned by Hikawa at Yoyogi Park before the Conception, offered as a sacrifice to bring the Vortex World into existence.

In the Amala Labyrinth, the souls of the slain Messians and Gaians can be seen preaching their respective beliefs.

Shin Megami Tensei: IMAGINE
After the Great Destruction, the Gaians established a new base of operations in Souhonzan, and continue to preach their beliefs of freedom. Their leader is Lord Doukan, one of the Seven Philosophers.