[quote]
In addition to that, the magical sound waves disrupt and erode any form of transient magic in their path, making it harder for them to mantain their form. As such, Nightmares would be slowly weakened and damaged, projectiles made with magic would lose a bit of strength and objects created with magic would be damaged little by little until they break, unless one invests energy to help them mantain their form. This does not have any effect on permanent magical effects like a magical girl's Arms or Emblem, however.
[/quote]

Added this to the CS in the Magic section, essentially a copy paste of the description given with some changes.