Malaise

"It itches so bad. Belly aches. I scratch but then I bleed... headaches, blurred vision... feel down and so itchy."

The Malaise, also known as the Plague, the Gloom, the Infection, and the Green Poison, is described as a virus that has been infecting the island within the Dead Cells world.

Mechanics

 * The Malaise functions in a point system, where a 10 point Malaise bar is shown above the health bar, only when the player has Malaise points or when they are playing in 4+ BSC.
 * At tier 10, the players's health is capped at 10% of their maximum; this means that 0 to 9 levels of Malaise do effectively nothing, but higher levels do bring the player closer to almost instant death at 10 levels, as Sudden Death Prevention is disabled and any hit has the potential to kill.
 * The Malaise can be acquired via the following ways:
 * The key elites in High Peak Castle apply 2 points of Malaise per hit. These are, more specifically, a Slasher, a pair of Dark Trackers and a Thorny. This occurs at all difficulties.
 * At 4 BSC and above, every enemy applies a point of Malaise upon hit.
 * The only exception to this rule are enemies spawned by other enemies, such as Corpse Juices, Corpse Worms, or Sewer Flies.
 * Eating infected food, which can only be found on 4 or 5 BSC, will give 1 point of Malaise.
 * Malaise can be cured with the following methods:
 * Using the Health Flask removes 5 points.
 * The mutation Necromancy removes 4 points when any Boss is defeated.
 * The mutation Alienation removes 2 points every time 5 Curse points are lifted.
 * Drinking Cough Syrup from Food Shops removes 3 points.
 * Drinking Small Cough Syrup spawned by Extended Healing removes 1 point.
 * Additionally, the mutation Dead Inside can be taken to increase the Malaise bar to 16 points, lengthening the time it takes to reach the critical level. This also increases some Malaise healing sources. The Health Flask removes 8 points, and cough syrups remove 4 points.

Origin
The Malaise has no clear origin. During the Alchemist's search for a cure, he theorised about where it came from. He states that some think the Malaise originated from the Slumbering Sanctuary: the sap there seeped into the Sewers, spreading the illness. The Alchemist also notes that the island's insects likely helped spread the virus. Piles of infected bodies were dumped into the sewer, and the infection appeared to rampage from there, although the Beheaded is unsure if they were dumped before or after the epidemic started.

Effects
The Malaise's symptoms include vomiting blood, itchiness, headaches, blurry vision, bellyaches, and feeling down. Left untreated, the Malaise leads to certain death. Since the infected were imprisoned and quarantined, the Malaise appears highly infectious.

The more extreme effects of the Malaise are highly unsettling. Mutations begin, and sometimes the corpses begin moving on their own. The end result of the final stages of infection is reanimation into hostile, mutated undead.

The virus affects humans and animals. Conjunctivius was a result of the mutations, and the Concierge was a victim of the virus as well. Meanwhile, the Beheaded's true entity is immune to the Malaise and only the bodies it possessed are vulnerable.

Treatment
Later into his research, the Alchemist found a way to reduce symptoms from infection, as well as a method for slowing down mutations. This was likely synthesized with the sap found within the Slumbering Sanctuary, which he suspected could provide the cure.

It appears that the Time Keeper had successfully kept the Malaise at bay via time manipulation, but it seems that this is exhausting to her, and the Alchemist suspects that time will not contain it forever.

Impact on the island
There is little sign of what the Island was like before the Malaise debuted, although it must have been at least somewhat prosperous. However, any chance at a good future on the Island was ruined by the Malaise and the King's response to it. The island's citizens faced civil unrest and focused their rage on the King, due to his cruel reaction to the appearance of the Malaise. The King demanded that the infected were to be imprisoned and hanged, even just upon the suspicion of infection. Eventually, he demanded that nobody was to be let out of the prisons, even if they served their time. What little of the villagers who remained on the Island met their deaths at the hand of the Malaise and the undead, or were slowly awaiting it locked away within the prisons.

Trivia

 * The Malaise could have possibly been influenced by the Black Death.
 * Bupleurum is directly referenced as a way to minimize the symptom of the Malaise.