Magick Power is the ability to cause change and transformation in accordance with the Will.
Within the International Nath Order this is the English name for Siddhi. Iccha, Jnana, and Kriya are Will, Knowledge, and Action: the triad that works it. An Adept is one who has attained to that sphere. It is not a grade conferred by initiation, and it is not a trick. Sri Kapilnath’s note separates magick from mystick. This page names the English phrase. Siddhi names the Sanskrit.