In the downward flow of nature, in a descending scale, the scalepoint of so -- and its chromatic counterpart, ra -- represent Vitality. Cards drawn below either point speak of energy sources and driving forces, of that which is crucial or critical.

In the upward flow of will, in an ascending scale, so and ra represent Challenge. Cards drawn above either point speak of challenges with broader implications than what is directly at hand, such as those of karmic import or those that impact the collective.