"In the last few years, a bizarre disease with varying symptoms has been reported in several isolated cases. The two things they had in common: Each victim's body turned against itself, and they all died. Because of that, we believe each subject was infected with GUILT." -Greg Kasal

GUILT (ギルス girusu), short for Gangliated Utrophin Immuno Latency Toxin, is an artificial disease developed by Delphi and used in medical terrorist attacks in 2018. It comes in eight strains. The first few strains were identified through letters that were received by hospitals who had GUILT hosts.

The strains of GUILT are developed using children with a specific genetic makeup, each abducted from all across the world. These children are designated Sinners, kept barely alive as a GUILT breeding ground. The age range for a Sinner is unspecified; Under the Knife implies them to be anywhere between 4-8, while Under the Knife 2 implies that children up to their early teens are used.

GUILT are characterized by the presence of chiral reactions, picked up by the Chiron Test (details not elaborated on) and different strains produce cells that emit different kinds of chiral reactions.

While GUILT can be treated, Post-GUILT Syndrome can manifest in their patients up to three years after onset. A significant plot point in Under the Knife 2 focuses on the hospitals trying to manage PGS victims with their limited resources.

It appears that overexposure to GUILT can cause genetic diseases, as it happened to Naomi Kimishima.

Types of GUILTEdit

Kyriaki Edit

Kyriaki creates lacerations on an organ until it can no longer function. This is the first and one of the most aggressive GUILT strains encountered.


Deftera manifests in pairs, and create tumors that saps the patient's vitality. Multiple bodies of Deftera are known to aggravate the disease.


Derived from a failed cancer treatment, Triti spreads across the organ, calcifying it and causing it to shut down. Though extraction looks simple, the improper technique can cause Triti to multiply. This makes it one of the trickiest strains to treat.


Tetarti creates toxic diverticula on an organ that swell until they release toxins. If the diverticula are removed, Tetarti manifests to create more, and release toxic gas in the process. Tetarti bodies are synchronized and each need a different medication to combat, but this GUILT has a very simple treatment method.


Pempti attacks the respiratory and the nervous system from the liver or lung, manifesting a layer of gelatinous fluid on the organ that hinders the organ's function. Pempti is particularly tenacious, with its core and the fluid supporting and regenerating each other. This is one of the most hardy GUILT strains; the development of the treatment is shown to be very complex.


Paraskevi moves through the host's body, instantly killing the patient if it burrows into the heart. As extraction of a full Paraskevi is very dangerous, it must be repeatedly cut down until it is small enough to extract safely.


Savato creates a web around the heart which nullifies and saps the energy of the victim's heartbeat so it can be used as Savato's energy source. The web is corrosive, capable of melting the scalpel blades that cut it. Without the web, Savato is still very fast, capable of creating lacerations and spawn faster than a normal doctor can keep up with.


Bliss inhabits Adam, keeping his body "alive". The Z-Cells that Caduceus Europe used to heal a war victim had been extracted from Adam's Bliss.

Bliss is the only GUILT that does not receive its name from a Greek day of the week, as well as the only known GUILT that is not operated on so far.


  • The names of the seven strains of GUILT encountered in gameplay are named after the Greek names for the days of the week.
  • GUILT seems to be capable to undergoing transformation into a different GUILT when exposed to airborne conditions, as Tetarti (Second Opinion 6-3) was able to turn into Immature Kyriaki, Mature Kyriaki and Paraskevi (Second Opinion 6-4), while Bliss (from Z-Cells) could turn into Pempti (Second Opinion 6-6), Triti, Immature Kyriaki, Mature Kyriaki and Mutated Deftera and Paraskevi (Second Opinion 6-7).
    • It also displays a transformation when Naomi's Rosalia Virus assimilates it just before the final operation of Trauma Team.
  • GUILT is based on several parasites found in real life.
  • In the Japanese version of the games, Tetarti and Triti have their names swapped. This is likely a mistake, as Triti (Tuesday) should come before Tetarti (Wednesday).
    vde Diseases and Conditions
Common Conditions AneurysmAppendicitisBurnCardiac ArrestCholelithiasisForeign ObjectHemorrhageInflammationLacerationTumor
GUILT KyriakiDefteraTritiTetarti (Diverticulum) • PemptiParaskeviSavatoBliss
Stigma CheirSomaOpsOnyxBrachionCardia
Post-GUILT Syndrome Post-KyriakiPost-TritiPost-PemptiPost-Savato
Neo-GUILT NousBythosSigeAletheia
Other Rosalia Virus (Twisted Rosalia) • Costigar DiseaseVaimahse Fever
Community content is available under CC-BY-SA unless otherwise noted.