Lore for Code Vein which will discuss vampiristic world and context of the situation in which the characters find themselves in.
Code Vein is set on a post-apocalyptic world after the event "The Great Collapse" happened. You play as a Revenant, a human that has been brought back to life to fight against the Lost.
Revenants were created by implanting an engineered BOR parasite into the heart of a human corpse. BOR Parasites (Biological Organ Regenerative Parasite) attaches itself to the heart of a creature that has lost vital functions and sends its own blood into the host, allowing it to regulate and control all organs, including the brain.
BOR Parasites where discovered before the Great Collapse, as dead creatures miraculously came back to life and eventually turned cannibal in a process called “Zombification”. Research into the phenomenon found that an unidentified life form had attached to the creature’s hearts and taken control of every cell in their host’s bodies. A procedure was developed, whereby the growth and contamination of the parasite is kept at a certain level through the process. Those who go through this procedure will sleep for a varying length of time that cannot be predicted, but will awaken with their mind and volition intact: A Revenant.
Revenants can only be killed by destroying the heart, where the BOR Parasite is located. Any other fatal wound merely causes the Revenant to dissolve into a mist that will reform later. Destruction of the heart causes the Revenant to die in truth, their body decaying into packed ash. While a Revenant can reconstitute, this comes at the cost of a part of ones memory. Usually, this is such a small memory that it is not even noticed, but occasionally a Revenant can lose large memories or vital ones. Revenants who recklessly get themselves killed repeatedly can lose almost all of their memories.
Revenant bodies produce and manipulate a substance called Ichor. Ichor is used to fuel a Revenants strength and the Gifts granted by their Blood Code. All Revenant weapons are designed to channel and utilize Ichor to enhance their combat potential. Likewise for their Blood Veil-- a piece of clothing that acts as a Revenant's 'fangs'. Revenant's use their Blood Veil's to drain foes for Ichor.
Each Revenant has a blood-type like factor in their blood personal to them alone, called their Blood Code. A Blood Code gives every Revenant unique Gifts, strengths and weaknesses. For all Revenants other than the Player Character, it is impossible to absorb and use anothers Blood Code, which instantly causes them to become Lost. The Player Character is an exception due to their Blood C being 'damage' in undefined circumstances. This makes them 'Void-Type', and able to use any Blood Code that they have acquired or been given.
Revenants require a steady supply of human blood, or blood beads as the one substitute. Without it, they experience Bloodthirst: The BOR Parasite stimulating it's hosts nervous system as a starvation response. If blood is not consumed, a Revenant will Frenzy, and become one of the Lost.
The Lost are Revenant whose BOR parasites have continued their infestation, spreading entirely through the body. As the BOR Parasite is no longer centralized to the Revenant's heart, the Lost are completely immune to death and will reform no matter what, this comes at a cost: The Parasite completely destroys the host personality, rendering them violent and cannabalistic. Lost are the primary threat in the city of Vein to its inhabitants.
The Great Collapse
There is little information available as to the nature of the collapse. The Collapse consisted of the emergence of enormous thorns from the earth, known as the Thorns of Judgement, across every city in the world. It is estimated that half of the human population of the world died to this event alone. After this came the appearance of monsters, known only as Horrors to those that bring them up, of an unspecified nature. The horrors were danger enough that it provoked the use of the BOR Parasite, originally intended to be utilized as a medical miracle, as a desperate and untested weapon. This resulted in the 1st generation Revenants.
The 1st generation were able to secure the immediate surroundings of the research facilities they were created in from the monsters effectively, but the side effects of being a Revenant became clear quickly-- without a supply of human blood, several Revenants frenzied and became the first Lost, which were as dangerous as the monsters they were originally made to fight and, most worryingly, were completely immortal. Lost who even experienced their heart's destruction reformed eventually. Realizing the flaws of the program, Project QUEEN was intitiated under the encouragement of Silvia Gregorio.
Project QUEEN was an attempt to enhance the effectiveness of the Revanants and to reduce their bloodthirst, a response to the frenzying of many first generation revanants into Lost. Little detail is available, but seems to have involves exposure of the Queen-- a young woman named Cruz-- to the blood of every organism the project could acquire. The project was initially a success-- the Queen did not experience bloodthirst, and was gifted with vast power which she used, in conjunction with the project, to create materials, drugs to aid in Revanant development and the Mistle, a plant-like organism that enhanced Revanant regeneration and soothed their thirst. The Revenants produced under the auspices of the Project are known as the 2nd Generation.
However, the parasite the Queen played host to as a result of this treatment caused her extreme pain. Eventually, the Queen lost her mind and Frenzied. The now wild queen caused terrible destruction to an already ruined city, and seems to have been the origin of the Miasma, a strange substance in the air that spurred Revanants to frenzy unless they use filter mask that was likewise developed with the queens aid. Operation Queenslayer and a desperate increase in the number of Revenant's to contain the Queen and the upsurge of Lost, which were by that point as much of a threat to humanity as the monsters they were created to fight.
The operation itself was an act of desperation, as the Queen further decimated the surviving population. Mass numbers of Revenants were produced from just about any available corpses to serve as troops, and equipped with servicable weapons with which to fight the growing horde of Lost of the previous Generations.
The Operation was ultimately a success, of a sort. The Queen's heart was destroyed. However, she proved to be unique again. Destroying the Queen's heart did not suppress her regenerative ability. The Queen was contained instead by dismemberment, each part of her body converted into a Relic that was in turn implanted into a 'Successor', a person who was biologically able to tolerate the Relic's presence. Each Successor was kept hidden within a Crypt-- an area enclosed by a barrier that protected the Relic and staved off frenzy, and that the Successor could not leave.
The Gaol of the Mists
Not long after the Queen died, the city of Vein was surrounded by an impenetrable Red Mist. Those who attempted to pass through it were met with an unimaginable pain, and nothing from outside came in. Those in the so-called 'Gaol of the Mist' were prisoners there.
The population within Vein was now predominantly Revenant due to the desperation of Operation Queenslayer, and the death of yet more humans at the hands of the Lost. Initially circumstances were not terrible. Bloodsprings appeared, large white plants that produced Blood Beads-- Pellets containing a fluid remarkably similar to human blood which slaked the Revenants bloodthirst for around two months for a large Bead.
Secretly, the Bloodsprings were the creation of the Successor to the Heart, who altered prexisting Mistle to form them into conduits for the blood the Successor provided.
The Miasma did not go with the Queen however, and without the Queen, Mistle that fell ill could not be treated as it required a medicine derived from her blood. The available living space for Revenants dropped as the Mistles sickened and went dry, allowing the Miasma to thicken until even the filtration masks could not cope with it. These regions quickly became abandoned to the Lost.
Worse, the supply of blood beads began to drop, slowly, as the Bloodsprings too began to fail. Chaos quickly engulfed the population until Silvia, with his Cerberus corps, established order with his Provisional Government. Most remaining humans were taken under their care, and provided with a safe and abuse free place to live (understandably for the Revenants however, this was in exchange for regular blood donations). The government levied groups of Blood Beads to redistribute them. While somewhat draconian, this limited the number of frenzies and restored some semblance of order. Humans were no longer hunted and Revenants ceased warring as much over the dwindling supply. The safe regions continued to shrink, however, falling to the ever increasing Lost population. The order the government imposed was temporary, at best.
Few BOR Parasites remained within Vein, most of which ended up in the black market for exhorbant prices. From these emerged the final, 4th generation of Revenants. Very often, these Revenants are made from the corpses of the quite young, presumably created by their parents in desperation.
Another issue presented itself, out of the eye of the public. The Successors were a flawed solution. While able to contain their Relics, the power of the Queen within them caused them horrible pain, as the Relic corroded them from within. Successors regularly came close to frenzy, and if they all did, the Relics would be free to merge, and the Queen would be ressurected. A Watcher was appointed, who would watch over the Successors in their sealed Crypts. If they came close to frenzy, they would be slain, and their Relic transferred to a new host.
After the Great Collapse, “Cerberus”, a revenants operation unit was founded by Silva’s Provisional government. They are tasked with overseeing the lives of all revenants and collect a regular levy of blood beads, which they are also in charge of distributing. They effectively began the restoration of order, and ended the hunting of humans for blood and wars between revenants.
Not all Revanants are willing to partake of human blood, considering it a loss of their humanity. Human blood is, however, a more potent and alluring food source for Revenant senses, leading many to preferentially consume it when possible. There is no evidence of addictive properies to this preference. Fortunately for the human population, the provisional government protects the majority of them from abuse. The dwindling of Blood Beads, however, is an increasing threat.
Even after the Queen's death, the Miasma continued to rise, and with the city of Vein. Bloodsprings appeared which provided a suitable substitute to pure human blood, but the rising Miasma that continued even after the Queen's death and the eventual drying of the bloodsprings caused further unrest for the predominantly Revanant population of Vein, reducing safe living space and available supplies of blood.