The Spirit Eye is a type of Eye Magic that allows the user to separate their spirit from their physical bodies and read the emotions or 'true spirits' of other people. It is used by the Independent Mage Zen Nashi.
When this magic is activated, both the user's eyes glow a bright mystic blue that have made some people comment that they actually look like ghosts. When the soul leaves the body, the eyes still retain the color but the person's expression has a daze look in it now.
This Eye Magic has no offensive abilities whatsoever. But its true powers lies in allowing the user to separate their spirit from their physical bodies. The user's spirit takes on an astral form, letting them fly, go through solid objects and remain invisible as to remain undetected from others, even Celestial Spirits can't see them. Another form is that this magic allows the user to read a person's emotions or their 'soul's thoughts, making it easy for Zen to know if a person is being honest or deceitful, good or bad.
However there are downsides to using this magic. The main and most serious drawback is that when Zen leaves his physical body, said body is completely lifeless and vulnerable, which is why Zen always make sure that he leaves it somewhere safe. Furthermore Zen's spirit can't remain outside for too long, as an extended time will cause his spirit to break apart and he will cease to exist. For the second ability, Zen claims that listening to too many thoughts of other people and their emotions could drive a person mad from listening to it all.