The Metalwood Saga / Reference Guide

Full-series spoilers

Otso Worlds

The Otso Worlds is a term from Tarathiel's initial translations of Ancient Eglarian texts, which he mistakenly believed referred to "seven worlds" housing the Defense Mechanism. The scholar Lashel later discovers that the actual word was satto, meaning "two," completely upending the theory by revealing the mechanism only ever involved two planets.