Mechanics[]
When within 10 feet of him he will hunt you down until he kills you or does not find you. You will hear giggling sounds if you are almost within the range. If you are within the 10 feet, you may as well just accept your demise. Vivacious has extremely fast speed so don't try to run either. Vivacious only won't kill you if you are in a vent, as he can't fit in there.