Medusa Eye

This ancient weapon of destruction is superior to all in a fight between the samurai. It destroys every fragment of any being that looks into it on a molecular level, preventing any regeneration or defense. It was so feared it was sealed, and over time people thought it had disappeared.

Overview
The Medusa Eye is a parasitic life form weaponized by the Mibu scientist Hishigi. The human shaman Akari has one Medusa Eye embedded in her left hand. The eyes have reptilian slit pupils, yellow irises, and black sclera. They damage any body in which they are implanted, evidenced by raised veins and discolored skin around them.

Hishigi’s medical knowledge enables him to manipulate a body's cells at the molecular level; he can alter, destroy, or even create new tissue. By applying this knowledge, he was able to implant dozens of Medusa Eyes into his own body to prolong his life after he contracted the Death Disease decades before the events of the manga. During Akari's time with the Mibu, Hishigi also implanted a single Medusa Eye in her left hand. The Medusa Eye possesses highly destructive properties and almost no weaknesses. It can only be destroyed by its own reflection.

General power
Life-Force Absorption

The Medusa Eye is able to drain the life forces of all targets within its field of vision, but it is most lethal to those who look into it directly. The potency of the Medusa Eye is such that it instantly drains a person’s entire life force, causing their body to crumble into dust. Only beings of exceptional willpower and strength are able to survive the true eye's gaze, and even they will turn to stone and eventually to ash. Even when sealed, it constantly feeds on the energy of its host, and as such is nearly impossible to remove or detect.

Kekkai (Barrier)

The Medusa Eye defends itself and its host from harmful spells. This defense is said to be unbreakable.

Espionage

Hishigi can use an implanted Medusa Eye to track its host. He is able to activate the Eye's power so that it will take over the host's mind.

Base
Using his cell manipulation abilities, Hishigi was able to recreate the structure of Akari’s eye. It is the size of a normal eye, but the iris is black and the pupil is white. The base form finds residency within the host body and takes on the appearance of a grayish mass and is able to connect it to the host’s brain by forming new nerve cells. The host then becomes an extension of the Medusa Eye’s parasitic body. The eye can be formed placed on the body, though Hishigi usually places it somewhere on the arm.

The Medusa Eye, when implanted in Akari, basically both strengthens and weakens her abilities. Its absorption is derived from the fact that it was created using her DNA so instead of turning people into zombified husk it turns them to dust. While the Medusa Eye drastically increases the bearer’s offensive abilities it drastically decreases her magical abilities. The Medusa eye grants Akari an unlimited supply of energy she isn’t able to personally utilize that energy. All the energy she absorbs either through the eye or by utilizing her own shaman ability instantly goes to the eye which then is slowly filtered into her body. When sealed the eye compensates by absorbing ambient energy from the atmosphere as well as from the bearer’s body. This means while Akari will have high reserves of energy that energy can only be utilized when manipulated outside of her body. The eye increases the potency of her Houriki spells she can’t perform any spells of herself. So while she can heal others she can’t heal herself.

Konsō (Soul Burial)
The second form of the Medusa Eye is unleashed in a process similar to how Saishi creates her Zombies. The energy he affixed to the Medusa Eye to control Akari is unleashed and spread throughout her body. This grants the bearer a unique and improved cell division mechanism which carries several advantages with it. Generally, during the normal process of mitosis, a parent cell will split into two identical daughter cells, having the same characteristics of the parent cell. These daughter cells can eventually split to form grand daughter cells and so on. However, the Enhanced Cell Division Mechanism occurs differently in the bearer’s body. In their case, the parent cell divides into four daughter cells instead of just two. This abnormality dramatically increases the rate of cell division and thus greatly promotes the accelerated formation of new cells. This ability enables amazing self-regeneration.

The original soul isn’t instantly lost but consumed as the personality implanted into the eye overrides bearers own. The body and soul of the bearer is slowly and methodically eaten away. In addition to a personality Hishigi can also implant combat knowledge. The Medusa Eye persona and the bearer are separate entities so at first the new persona can’t use the bearer’s original skill. However the eye constantly spreads throughout the body as it absorbs the bearer extending its power to that part of the body and gaining the bearer’s abilities. The bearer’s abilities, the combat knowledge combat knowledge implanted into them and the catalyst of the Medusa Eye makes them unbeatable.

Petrification Blade
This is the main offensive weapon of the Konso by altering the consistency of the cells in the area around the Medusa Eye, the user shapes them into a sharp weapon. Then the cells are packed closely to increase the density of the ‘blade’ and are hardened, making the ‘cutting arm’ more than a match for metal weapons. The absorption abilities of the eye are refined to a strength similar to when its base form is sealed, so in addition to constantly absorbing ambient ki from the environment it also absorbs various minerals and metals such as Titanium is the ninth most abundant element in the earth's crust. Since the cells used to ‘forge’ the blade are constantly created and replaced, the blade can extend to great lengths without reducing its thickness. This also means weapons of any size can be formed and take certain desired physical traits depending on the situation. The blade may be used to restrain opponent’s weapon or even the opponent themselves very efficiently by using the blade to entangle them. The more blades are made, the more cells are required and therefore the more energy is used up

The blade causing petrifaction on anything it cuts. It is a slow process that increases the more victim is cut until the entire object has been turned to stone, which will eventually crumble into ash.



Cable Cross
This is a technique that once the Medusa Eye has fully consumed the bearer allowing the blade to be extended from any part of their body instead of just the implanted ares. The Medusa Eye's blade splits into multiple extending tendrils and are fired into the floor, since the Medusa Eye is parasitic in nature anything the blade comes in contact with becomes an extension of it, allowing the blade to take control of additional host bodies, using them to increase its strength. When used on the ground anything in contact with becomes and extension of the tendrils. They emerge from various random points from the ceiling, floor, trees, buildings and walls to strike the foe from numerous angles all at once.

High Core Crusher
As the Medusa Eye expands the bearer’s cell membranes become "armored" with with the various molecules the eye absorbed metallic or otherwise for strength. Titanium seems to be most substantial element used as it is recognized for its high strength-to-weight ratio, which means its use throughout the body of bearer does not affect their weight drastically. It is a strong metal that has excellent malleability without shattering. The absorbed minerals lead to faster protein synthesis due to conductivity within the cell and increased excitability in electron transport function, as well as energy released. They are also directly attributed to an enhanced muscular system, causing the body to no longer generate fatigue poisons. Rather, the body constantly expels waste products during its accelerated respiration through exhalation. The cardiovascular and respiratory systems become many times more efficient than those of a normal human being. The metallic minerals also increase the tensile strength of the tendons and bones. It is this increased physiology that allows the bearer to perform this incredibly fast and powerful technique. The Medusa Eye blade increases its size and shape to form a large drill. The bearer then launches himself at the enemy, drill first. The attack generates sufficient speed and force that the wind as bearer flies towards his target can destroy the walls, floor, and roof of a building.

Weakness
A simple way to defeat the Medusa Eye is to make bearer look directly at it causing them to turn to ash. Deprived of it source of nourishment the Medusa Eye will cease to function and disappear. The Eye is also not immune to its own ability if the eye is destroyed the bearer is freed from its influence and they are returned to normal. If this this is done while it is in Konso all the places turned to stone by the petrifaction blade become open wounds.