His Mechanic Is Simple. The entity signals its arrival by flickering the lights. You must never stop moving for the duration of the event. The threat lasts for exactly 5 seconds. If you are stationary for 1.5 seconds (even if stuck against a wall), you will be killed.
When His Eyes Open. That Signalifies He's Making Sure you're standing. in. one. spot. don't let him see you move at all. or death :) Sin: Instability