Silence

Silence is a spell that allows a mage to silence a target from speaking. This was supposed to be used by Louise de la Vallière to silence Saito Hiraga because of his random ramblings when he was first summoned and Louise still did not understand his speech.

Tabitha was later shown to use this on Kirche von Zerbst, whom she anticipated to babble at her. As a result, Kirche continually spoke to Tabitha, but the latter does not hear anything from her. Tabitha later cancelled the spell and was able to hear Kirche speak again. Based on this experience, it is unclear whether the user is the only one who cannot hear the silenced person, or if the target is literally silenced and unable to speak with sound.

Trivia

 * It is unknown if this spell is being taught to freshmen at Tristain Academy of Magic, but Louise de la Vallière once said that she was able to learn the spell during her first year at the institute.
 * Louise de la Vallière once attempted to use silence on Saito Hiraga by chanting Ansur Ver Ang. This, however, was the incantation of another spell that successfully worked.