Noah and King Elbas weren't strangers to the void. Still, their mission through that harsh environment had happened countless years ago. Their whole existence had transformed in that period, allowing them to inspect their surroundings with new eyes.
The void was still the same, but the space-time array was clearer now. Both Noah and King Elbas could sense laws that they didn't wholly understand mixed with true meanings belonging to Heaven and Earth's system. They were still inside the rulers' range, but the universe had already started to show part of its real face after crossing the sky.
In theory, the monster was impossible to recognize due to its innate emptiness. There was simply nothing to see, but Noah and King Elbas sensed it, and the same went for Sepunia. They could feel the presence of something that didn't exist, and the event naturally created odd reactions in their minds.