Misc 1 Volume 1

Just then, Izayoi felt a Tinnitus at his ears. This is because, though
Izayoi might not be as good as Yō in terms of hearing but his senses
were far better than normal people and that allowed him to recognize that
frequency of sound waves.

(That sound wave......Oh, I see, so that‘s how it is?)
Seeming to have understood everything, the corners of Izayoi‘s lips
curved upwards in a slight smile.

The invisible knight used the Gift of Hades Helmet to completely erase
his presence. This Gift, which was created to assassinate the Gods,
could hide the user‘s heat signature, smell and even sound. Even if up
against a visually poor snake that used its sensitive heat probe organ
......it will not be able to capture the user‘s location.

(The enemy‘s at a position of ten meters away observing the situation,
there‘s no problem, he doesn‘t seem to have taken notice yet.)
However, this Gift of Invisibility had a fatal weakness.
This Gift‘s ability was to make one transparent rather than
completely permeable.

For example, the sound waves emitted by dolphins or bats and
submarines which copy that with a sonar function to rely on the reflected
sonar waves to explore the area. That would be able to counter this Gift
of Invisibility.