A chance encounter at a Fanueil Hall restaurant between a yoga instructor and a Brooklyn man turned into a terrifying ordeal when the self-described Satanist threatened to kill her “without blinking an eye,’’ officials said.

Christopher Cori, 20, pleaded not guilty to criminal threats and harassment charges in Brighton Municipal Court where bail was set at $100,000 cash. He is expected to undergo a mental health evaluation at Bridgewater State Hospital in the coming days.