"The one that covers" was a parasitic organism that could physically enhance and transform the host.
The parasites were discovered by Code Talker upon researching the remains of The End after Operation Snake Eater in 1964, and later reviewing the records of The Pain. After studying them and even allowing The End's parasite to assimilate with his own body, Code Talker had the parasites sealed away.
The parasites were later used in the creation of the Parasite Unit and the return of Quiet to active service. Although they were generally parasitic, Quiet and presumably Code Talker and The End's cases were closer to symbiotic rather than truly parasitic, as they also gave a lot of benefits to the hosts.
Some hosts generated a pitch black gas, which could be used to contain and control metallic archaea. The parasite acted as the host's skin, to a variety of effects. A primary effect was providing camouflaging abilities to the point of invisibility, phasing layers of flesh in and out of the visible spectrum to the point where the muscular system was sometimes visible. The black gas appeared when the subject vanished into thin air with their powers. This vanishing ability also can make the host at least partially intangible in the form of the host turning partly gaseous, which allowed Quiet to phase her hand out of handcuffs, while she nor the Skulls can phase through solid matter.
Also, while Quiet's flesh would only briefly phase in and out of the visible spectrums and would distort when she was using her invisibility or turning partly gaseous, the Skulls would show their muscular systems and internal organs while using their powers. Superhuman mobility, strength and resilience are highly common amongst these kinds of subjects. In addition, weaponized subjects could float down while mid air and slow their falls, a possible side effect of their gas like transformation ability. This transformation could even allow a host to move faster than vehicles. In return, the host becomes a source of nourishment of some sort for the parasite.
The Skulls, who were infused with metallic archaea, had other abilities uncommon to normal hosts. The Armor Unit were named so for their ability to reinforce the skin to a form of hardened armor created through calcification of the the skin. This calcified material can be shot from the body as a projectile or infused into the ground to cause sharp spike like structures to burst from it as a means of attack. For defense, the Armor Unit could use the materials infused into the ground to cause a wall like structure burst from the ground between them and their attacker. These structures could degrade when not in use but could also be destroyed by direct explosions.
The Mist Unit could manifest gas clouds that could turn metal objects, no matter the mass or size, to rust instantly, which allowed the Mist Unit to turn a helicopter to rust and make it crash. The gas also obscured vision, as well as sensor, scanning and tracking technology useless. The Armor and Mist variants of the Skulls could even use their gas to make their victims zombie like infected, called puppet soldiers, that follow them into battle. This form of control was similar to The Pain's ability to control insects through his pheromones. The very presence of the Armor or Mist Units could be enough to turn a soldier to a puppet.
The parasite could also replace lost organs of the host, as seen in Quiet's and Code Talker's replacement of their digestive systems to make them photosynthetic, as well as the modification of her respiratory system to be cutaneous (through the skin) rather than pulmonary (through the lungs). Quiet was also resuscitated near instantaneously by sunlight alone after being drowned. The End had similar abilities, causing him to rapidly heal in sunlight, have superhuman resilience, and survive exposure from lack of shelter as long as he was exposed to the sun, air and water. He, like Quiet, also possessed an superhuman resilience to gunfire, as bullets and injuries did not slow either of them down or inflict lasting damage unless such damage was continuously done before they could use direct sunlight to recover.
A host of the non-lethal strain of the parasite could be identified if black blotch markings could form around the eyes due to emotion, as Quiet speaking Navajo to Code Talker caused such markings to briefly appear on his face. These markings also appeared on Quiet's face when she was insulted by Miller, while she revived from drowning, and generally, times when she was in direct combat or intense danger. Alternatively, a host of the parasite that also possessed metallic archaea in their bodies, such as the Skulls was seen with greyed skin and darker skin pigmentation.
Quiet's infection made her senses and reflexes superhumanly acute, allowing her to shoot an oncoming jet fighter pilot from a helicopter several miles away, as well as shooting one of Ocelot's revolvers through the propeller blades of a helicopter without hitting them, even despite the great kickback of the weapon. Alternatively, the Skulls had poor senses and reflexes, which weakened their reaction time. Their hearing and sense of touch was severely weak, which caused them to be almost unable to detect enemies presences without their sight or being close to them. Furthermore, they tended to stumble when walking. This made them vulnerable in combat and more reliant on their abilities. These weaknesses also applied to the zombie like infected made from the victims of the armor and mist units of the Skulls. On the other hand, both of them were more resilient to pain and discomfort due to their numbed senses.
Some parasites bestowed special abilities upon their hosts if compatible:
- Expanding natural human lifespan to approximately one-hundred years.
- Replacing and replicating the processes of the organs of the digestive system.
- Superhuman strength, speed, agility, resilience and durability.
- Near-invisible camouflage by augmenting pigments in the skin and seemingly phasing the users tissues in and out of the visible spectrum, though users can also make only their skin and outer layers of flesh invisible while the muscles and bodily systems underneath remain seen.
- Covering the skin in a black rock-like material as armor which could be projected from the body into projectiles or into the ground to cause spike like structures to burst from it, both as a means of attack.
- Photosynthetic skin that allowed a user to recover from trauma, damage or toxins in a matter of seconds while they are exposed to direct sunlight.
- Dispersal of a mist to obscure sight and turn metal to rust instantaneously on contact.
- Releasing heterogeneous pheromones that attract and have complete control of hive insects.
- Releasing high amounts of adrenaline to override pain.
"The one that covers" had several variants of the parasite, each with its own properties.
Mist Parasites were a variant of "the one that covers," and were most frequently found within Mist-type Skulls. They were capable of generating a dense mist while the host was in battle.
Camouflage Parasites were a variant of "the one that covers," and were most frequently found within Camo-type Skulls. They allowed the host to blend into the environment to such an extent that they could even throw off tracking abilities. It was heavily implied that the sniper Quiet had been infected with this variant of the parasite when undergoing parasite therapy due to injuries sustained from XOF's attack at Cyprus. In large part because of these abilities, the ones who had these were generally snipers.
Armor Parasites were a variant of "the one that covers," and were frequently found within Armor-type Skulls. They allowed the host to employ calcification to protect their bodies. These variants were also implied to be those that a rival of No Alert released at one of their FOBs.
Behind the scenes
The parasites are a major element in Metal Gear Solid V: The Phantom Pain.
In one of the cassette tapes, it is revealed that, in addition to The End's parasite, The Pain had parasites as well. The End's parasite would later be transferred into Code Talker.
- "Mist Parasite
Parasites extracted from Mist-type Skulls. They possess the ability to produce a dense mist. Required for developing and using parasite supply cartridges."
- ―Mist Parasite description in Metal Gear Solid V: The Phantom Pain
- "Camouflage Parasite
Parasites extracted from Camouflage-type Skulls. They possess the ability to blend their host into its surroundings by altering their pigmentation at will. Required for developing and using supply cartridges."
- ―Camouflage Parasite description in Metal Gear Solid V: The Phantom Pain
- "Armor Parasite
Parasites extracted from Armor-type Skulls. They possess the ability to protect their host's body through calcification. Required for developing and using parasite supply cartridges."
- ―Armor Parasite description in Metal Gear Solid V: The Phantom Pain