He is tall. He is silent. He walks at exactly 1.5x your sprinting speed.

This topic appears to be highly niche, possibly a new indie horror concept, a specific fan creation, or an emerging internet myth. The Nightmaretaker Guide

By using the Nightmaretaker techniques, you are essentially training your brain to override the amygdala's panic signal in real-time. A study published in the journal Current Biology showed that lucid dreamers who confronted nightmare figures experienced a measurable decrease in the electrical activity associated with fear.