Quadratic Key

Quadratic Key is the name given to any high-energy source that detonates a Quadratic Sphere. The Quadratic Sphere is a physical formation of Heraldic magic, and its potential energy is released through activation by a key. Due to the extreme energy-to-size ratio required to activate a sphere, keys tend only to be energy stones and contained matter-antimatter reactions. Expel is a rare planet that is naturally laden with energy stones, and so the Ten Wise Men were able to activate a Quadratic Sphere of their own (the Sorcery Globe) to bypass the protective force field of Energy Nede.