In the anime Nurarihyon no Mago, when Rikuo uses Kyoka Suigetsu, enemy attacks appear to pass through him as if he were an intangible ghost. Is the technique creating illusions or actually making him "untouchable"? It is stated that he can "distort opponent's perceptions" with the technique, but it is also said that he can "distort his presence, even when he is still there". So: are enemy attacks passing through illusions, passing through him, or a combination of both these things?
The ability is named moon mirror because as it was explained "nurarihyon is the reflection of the moon" a distortion, and I would say that it means he can first , slow enemy's perception of him to move faster like an after image technique or second, his body ripples like water to allow him to move around attacks. His only weakness like this is cutting the fear which means his aura is masking himself but those two options are viable. I believe it is a bit of both because he can slow perception to allow him time to move but the ripple allows him invulnerability against weaker attacks because water can only ripple so much.