The Asmodeous Project, while never called that in public, was Edmund Bancroft's brain child and his intended method for gaining control of the Earth. He initially nit as an attempt to cure cancer and, for twenty years, that's what the public believed it to be. As a matter of fact, the project did in fact manage to create a virus that would cure several types of cancer, and these were used as evidence that everything was working. In reality, a deadly disease was being created, one that would cause so much fear and panic that no one would dare to oppose him.
Rather than using a virus, Bancroft settled for using the Yersinia Pestis bacteria and modifying it until it became a "Superbug", immune to all current antibiotics. The constant additions of DNA to keep the bacteria immune to modern antibiotics led to some errors, but the bacteria still did its work well. In order to make the disease even more terrifying, Bancroft added DNA from the Ophiocordyceps Unilateralis fungus. The intended effect was for the bacteria to consume the person from the inside out in order to make the death as painful and messy as possible, two things that Bancroft needed to spark the kind of fear he wanted.
However, adding the fungus DNA resulted in some other, more horrifying consequences. The disease alters the infected person's perceptions of reality, causing them to attack anyone who is not infected. They feel no pain or fear, they just attack, sure that their survival depends on it. And, as they blindly lash out at those who the disease has not taken hold of, their bodies deteriorate until they can no longer stand, or even crawl. And still they are alive.
In addition to the altering of the infected person's perception of reality, there are other side effects caused by errors in the DNA of the bacteria. These effects vary between people with different body types and degrees of resistance towards the bacteria and range from releasing massive amounts of adrenaline into the person's blood stream, drastically increasing their strength and stamina, to increasing their ability to see, hear and smell.
Not wanting to wipe out all the population on Earth, Bancroft programmed the bacteria so that, once in a host, they will reproduce and their offspring will die after four days, no matter at which point after the initial infection they were spawned. After the initial infection via the air, bacteria can still spread from one person to another via bodily fluids, although the bacteria will still die four days after their initial host was infected. As a result, it is possible to survive the disease, although the survivors will likely be so badly damaged, both physically and mentally, that it might have been kinder that they had died.
