She is the infinite power of the universe from which all worlds, suns and life emerge and return to. She is fearsome because the terrible power of the universe appears fearsome to mortals. Quite a bit, according to Madhobima. For instance, people like her realise in a very palpable manner what time is. Time is everything - it is in its unravelling that matter and energy find form and meaning.
Time even has everything to do with life and death.
We are time capsules contained in one sperm and ova. Time spins out a life and at different phases makes us different things - starting from turtle to fish, infant and adult. When time runs out we meet death. The yogi can control many things including time. They key to this control is through the control of breathing.