What a strange world, only four contries, "Planeptune" leaded by Purple Heart and Purple Sister, "Lastation" leaded by Black Heart and Black Sister, "Lowee" leaded by White Heart, White Sister Rom and White Sister Ram, and "Leanbox" leaded by Green Heart.
The leaders are deitys that get their powers from the faith that people have in them, which transforms into Shares. It also seems like the four nations have higly advanced technology, and by logic, higly advanced medicine, though, it seems like this world didn't suffer from an epidemic before, for now...
A Bacteria is born in the Dimension of "Gamindustri" for unknow reasons, with the objective of wiping out humanity, but with the higly advanced medicine and the deities themselves, is not going to be an easy task for the pathogen to achieve. Will it reach it's objective? Or is going to be eradicated in the try? We shall find out...
The disease starts in Planeptune, it's weak and will take a wile for it to expand, especially with the medicine that this world has, but after managing to infect a few people and develop a drug resistance, it shouldn't be hard to infect the population. The Bacteria needs to be stealthy, not developing any sympton until everyone in this world is infected.
It seems like this world has an unique fauna, the 'dogoos' being part of it. They could help by spreading the disease to the ones that will figth them.
After five months, more than the 60% of the population of Planeptune had the disease, it was going well for the pathogen, but it could not be stuck at Planeptune only, it had to reach the other nations. By the dogoos, the disease could reach to Lowee. It was a cold nation, and without the proper resistances, the disease could never expand at a good rate. Three months have passed and the entire population of Planeptune had the disease... Well, almost, 99,8% of the population had the disease, Purple Heart and Purple Sister were still healthy, probably because they are godesses. The Bacteria needs to grow stronger if it intends to spread to the deities.
The disease evolved an cold resistance, it would just need months to infect Lowee completely.
Again, by the dogoos, now the disease has reached Lastation, but, unlike the other two infected nations, Lastation seemed to be more wealthy, a better drug resistance would be needed for the disease to survive and spread in the nation.
After ten months, all of Lowee was infected and due to the better drug resistance, all of Lastation was also infected, excluding the godesses of the nations. Only Leanbox is left healthy, but the dogoos couldn't help to expand the disease there, it could only reach there either by transmission in the air or the water. After evolving the capability of be able to survive outside the body in water, the disease managed to get to Leanbox, in just 20 days, the whole nation was infected, no living being in Gamindustri was left healthy except for the godesses. Now the real terror could start...