Editing Creating Magical Effects (section)

===Unweaving===

This tries to tear apart a n existing spell. You make a challenge against the difficulty of the original spell (although your difficulty might still be modified by distractions or Resonance). You must have the Spheres necessary to have cast the Effect,
and you must have at least the Apprentice-level Prime Sphere. If you win, the spell loses one grade of success. Unweaving can degrade the duration of a spell. If the spell has no grades of effect left (i.e., it’s down to a simple Effect),then an unweaving destroys it