Power Syllables are the syllables utterable by living beings that resonate with the membranes between alternate realities. This resonance allows beings to alter reality, making it the closest thing they have to actual free will.
Historically, Power Syllables were identified by esoteric traditions like Kabbalah and Theosophy.
They are still present in modern linguistic speech, but when uttered without structured order, they are relatively powerless. The most powerful Wordspell the average person casts is the utterance of a powerful cliche that has found success due to the luck of its sequence of vowels.