Complete all other plagues on Brutal or $1.99USD
October 24th, 2016, Mutation 13 (Android)
The Shadow Plague, also known as "Nox Aeterna" ("Eternal Night" in Latin) in the game, is a new special plague added in the Mutation 13 update. It can be unlocked by paying $1.99 or by beating all of the other plagues on Brutal. Players who bought the full expansion pack will get the Shadow Plague for free. It combines all of the other special plagues into one. Unlike some of the other plagues, this plague is more active, difficult, and aggressive. As vampires constantly kill humans at night, you can potentially get noticed very easily and eliminated quickly. This plague is available on the iOS, Android, and PC versions of the game.
In-game Description Edit
Sentient, mutagenic pathogen. Triggers a powerful thirst for blood!
The Shadow Plague has two hosts: Vampires and Humans. Vampires kill people at a constant rate. You first start off with one. They infect humans in the country they're in once you have evolved a trait called Shadow Blessing. The vampire also has a health bar which can fill or drain, depending on the circumstances. Vampires have three active abilities: Blood Rage, Build Lair, and Vampire Flight. Blood Rage always costs 1 DNA point to activate, unless you use the gene Brawler, and will cause the vampire to attack any Templar Command Posts or WHO laboratories in a country, If neither is present, the vampire will begin to kill the country's population at increasing amounts per day. This generates DNA points and can also heal the vampire if Dark Ritual 1 & 2 are evolved. Blood Rages can be stopped by "activating" it again. Lairs can be built at any location in the country a vampire is in. Lairs generate DNA, and the amount increases with the more people infected, quite similar to Ape Colonies in the Simian Flu. Vampires automatically heal at a slow rate when in a lair, and that rate can be increased by evolving abilities in the "Vampires" section. If the Templar Command Posts have activated their military protocols, they will send attack drones to target lairs. If the drone is not destroyed with a Blood Rage, the lair will be destroyed after a small amount of time. Vampires can instantly teleport to any lair if Shadow Portals are evolved, and can also help the spread of the Shadow Plague in the country it's in if certain abilities are evolved. There is a gene which makes the vampire harder to detect if it's in a country with a lair in it. Therianthropy allows the vampire to move around the world, the shadow plague counterpart of Travel. Therianthropy must be evolved for Shadow Portal to work. The range of Therianthropy is initially small, but it can be expanded by evolving Travel Speed 1 and Travel Speed 2. The speed at which the vampire travels is unaffected by land or water.
In the symptoms section, you can evolve a symptom called Vampiric Awakening, which is the only symptom in the plague that increases lethality over 20 points and eventually also creates a new vampire. That symptom is reusable. There are also symptoms that force the infected to become slaves, and they will bleed or sacrifice themselves to heal and help you. You start off with no transmissions in the Transmissions section, and only one symptom in the symptoms section: Shadow Blessing. It is a free symptom that, when evolved, unlocks the entirety of your transmissions, and the majority of the main symptoms.
The Shadow Plague is quite different from the other plague and disease types, but it shares a lot of similarities with the other Special Plague types. Like in the Neurax Worm, there is an alternative victory condition that involves evolving a trait that enslaves humanity. Like the Necroa Virus, you have to deal with the Templar Command Posts, who function similarly to Z-Com in that they can kill off your Vampires. Finally, like the Simian Flu, you can set up lairs where a Vampire can restore lost energy, generate DNA, and hide. Also, to an extent, WHO laboratories are somewhat similar to Gen-Sys. If the cure reaches 100%, not only will all the infected be cured and back to normal, a piece of information will pop up on your screen saying that those with the cure have blood that will poison the vampires. As vampires constantly kill for blood, their health will slowly go down over time, and you will eventually lose.
Unlike the other Plagues, you start out with no Infectivity and steady Lethality (from needing to feed on blood) wherever a Vampire is located. Also, unlike the Special Plagues, Vampires cannot fly just anywhere in the world. They are limited to a relatively small radius, unless you've evolved Shadow Portals, which can only work in countries with Vampire Lairs built.
Like the other special plagues, this special plague has a new colour of infection that covers countries as they are slowly infected. The Shadow Plague uses the colour purple. Interestingly, the Shadow Plague has three ports to fill with up to 15 different genes unique to it. This appears to be part of a trend toward the increase of unique genes in the Special Plagues, from none with the Neurax Worm, to one with the Necroa Virus, to 2 with the Simian Flu.
Because there is only one individual infected with the Shadow Plague at the beginning of the game, and that individual can be moved to specific countries, it's possible to do great damage to the world population and cure effort before you are "noticed". Abilities evolved to fight the Templars can also be used to weaken the world later on. It's also possible to use Blood Rage to completely wipe out the world population, though to do so would involve a great amount of time and patience, and the Templars would also have to be dealt with.
Additionally, the Cure Effort will not start unless Shadow Blessing is evolved, so Blood Rage can be used to increase the amount of DNA Points a player can work with.
It's possible to use Blood Rage to attack and completely consume countries, such as Iceland, to decimate the Cure Effort before you evolve Shadow Blessing, allowing you some room to work with when you evolve Shadow Blessing.
Since people die each night your Vampire is in a country, it is possible for your Vampire to be spotted early in the game by the Templars, who can take action against you. This is bad for a weak Vampire, who can be easily killed by a Templar Base if it hasn't evolved sufficient Abilities. Also, if a country has been wiped clean of its population, the Vampire will starve if it is not moved to a new country. However, interestingly, a vampire in a lair with all the healing abilities will not starve. This is because the huge healing rate overrides the starvation effect. Because you only have one Vampire to start off with, if that one Vampire dies, the game is over. Not only this, but if a country has a WHO Lab built, they can spend much more money to cure the Shadow Plague. However, the cure progress gets set back if your vampire destroys the labs.
Also, the Shadow Plague is not a fast-spreading disease unless certain abilities have been evolved, making it hard to both transmit the disease and combat the Templars at the same time. Therefore, it is advised to concentrate on taking care of the Templars first before concentrating on spreading the Shadow Plague.
In addition to this, the Shadow Plague also does not have Abilities for directly combating the Cure Effort. It makes up for this with the aforementioned Blood Rage's ability.
Please see Shadow Plague Strategy Guide.