Mystic Eyes of Death Perception

The Mystic Eyes of Death Perception (直死の魔眼) are a type of mystic eyes that are considered to be such a rarity that they are thought not to exist at all. They are possessed by Sting and many other unknown mages.

Workings
The Mystic Eyes of Death Perception can be called a circuit that opens up in the brain and eyes to allow the user to "perceive death", the conceptual "Death of an Existence", as visual signals in the form of Lines of Death (死の線) and Points of Death (死の点). Their usage is not entirely dependent on the eyes of the user, as they can still "see" lines should they go blind or gouge them out. Rather than "seeing", it is more like they are "observing" everything at a higher level. They are invisible to normal people, only accessed through perceiving the natural flaws with overly strong spiritual sight by looking through channels that normal people cannot perceive. In perceiving death, it can be said they see the Root itself. They are similar to the eyes possessed by the Celtic god,, which were able to actualize death simply by looking, and they have not been possessed by anyone else since then.

The ability to perceive the death of a being or object depends entirely upon the user's perception of death. The brain and the Mystic Eyes work as a set, so having different "specs" allows for great differences in the users' abilities to perceive death. They show the death of things, the weak points where everything is most easily broken and the imperfection in everything that will break down one day. They can be said to see the fate of all things, seeing the future, allowing them to see death. While there is a difference as to when an person or object will "end", it is certain that they will all arrive at that point because death is not something that "arrives", but rather is something already contained within an object at its creation and certainly bound to happen as part of the principle of causality.

Lines
Death emerges to the surface of an existence as lines, and cutting along them will result in "Death", regardless of the constitution or properties of the object. They have no particular structure, so the can be described as solid, black "zigzagging scribbles" all over the world, even within the air itself, that look like cracks. They are harder to see during the day due to the light, but emit a sort of glow at night. The lines of a living organism will keep changing position as long as it is alive, and those Sting perceives are constantly moving and irregular. They can be traced with any sort of object, effectively "breaking" the person or object along the line, cleanly cutting it without any need for force. The object tracing the lines "sinks into it", and although a finger will fit into the thicker parts, thinner objects like rulers or knives are more effective. Sting does not attempt to actually trace lines with his fingers.

Gilgamesh theorizes that the lines are something like the weakest parts of the joints between molecules in an object or a predesignated switch within the genetic makeup that activates the death of the object. Those of Sting are described as "lines where the substance breaks easily", while those of others are described as the "the concept of longevity given form" rather than lines at which "an object can be easily cut apart." Completing a cut makes it impossible to heal under any circumstances. The lines that are cut cause the corresponding part to die, making them never able to move again even if the main body is alive.

Beings will have different amounts of lines depending on their complexity. Humans will have a countable amount in geometric patterns. The deceaced have numerous lines all over their bodies that make their appearance hard to discern. Members of other races/planets will have very few "parts vulnerable to death." Those without physical bodies are also able to be killed.

Points
Points of Death are from where all lines seem to flow, resembling blood vessels. There can be a number of them on an object, and, whereas the lines are "where things die easily", the points are "death itself." The eyes do not actually kill "the body", as the power of killing someone's life is very common in the world. The "points" seen by the eyes end the very meaning, the "existence", of whatever is "killed." The destruction, the extinguishing of life that comes afterward, is only a side effect of destroying their existence. Striking the point makes the entity completely cease to function. What "makes a living person a living person" or what "makes a hallway a hallway" is ended in the simplest way, unraveling its existence and making it no more. This makes it possible to kill the soul without harming the body, allowing for the destruction of one of two souls in a single body without the death of the other soul or the body itself. The weaker soul is the one that will be ended, so it is a battle of strength in that case.

Points can be pierced by sharp objects. Piercing a point effectively “erases” that object from existence, causing the entity to completely cease in function. It can stop certain inherent properties such as momentum, toxicity, and generally any effect it may impose on it's surrounding. Disease, poison, and corruption like that of being turned into a dead apostle can be completely negated. Living things whose point was pierced get “stopped” and, as a consequence, die. Those who have accumulated an exceptionally large weight of existence take longer to die because there is more of their existence that needs to unravel. It is absolutely permanent, and can't be reversed or bypassed.

Limitations
The ability to kill something with the eyes requires the user to actually strike the target, so those physically above the user will easily be able to avoid them with little worry. While Ceaser kills Gilgamesh at his full available power with a perfect sneak attack, he would be able to easily avoid him if he were to actively attack her even in his drastically weakened state. In order to use the eyes, the users must be a mage and have control over black magic and death mana.

Another thing is that the eyes can't be achieved by anyone without Ryougi blood. Its virtually impossible to do so. This brings up questions as to whether Sting is actually Sting Ryougi. Anyone who tries to activate the eyes without Ryougi blood will ultimately lose their vision entirely and slowly begin to poison their own blood.

Users

 * Sting
 * Shiki Ryougi