A Pillar is a Sacred Artifact that can retain new memories formed within a loop, even after the loop resets with the Great Flood of Time. They support the worlds of their origin. Pillars also refers to the wielders of such Sacred Artifacts. It may also refer to anyone or anything that can resist being washed away by anything. A person who has the role of recording the remnant of the World after its destruction is called World Pillar, though said person may not necessary be Transient from the world that Pillar belonged to.
In a more general sense, pillars refer to things that connect AETHER and NETHER together. Conceptually, this relates to connecting opposite concepts such as Yang and Yin, light and darkness, or sky and earth. The permanent Gates of Tokyo, pillars of light that penetrate the earth and the sky, are also pillars, according to Breke recalling the memories of Azathoth.
Individuals may also train to achieve enlightenment and become Pillars, according to Motosumi. He elaborates that by isolating oneself in the mountains (representing the Ten Realms), studying the Three Mysteries of Esoteric Buddhism, and practicing secret rituals, one can become a Pillar and learn the mysteries of Vajra and Garbhakosa.
Relation to Representatives
Representatives are often but not always Pillar owners. Similarly, Pillar owners are not always the Representatives of their worlds. A Representative that is also a Pillar has a major advantage in the Game, having a clear objective to win for their World while being able to refer to the memories of past loops to give them an information advantage in future loops. On the other hand, due to memories and feelings from the past loops being piled up continuously, the person's identity can risk eroding away to nothing once the limit is reached.