As far as the isekai goes, I think I’ve nailed down most of the tweaks I’ve made to the history of Northeast Asia. I know Russian history has to have changed, due to a magic-carrying comet going smack into part of Siberia. Possibly near Lake Baikal, that spot’s already got plenty of weird….
Now I need to figure out how the rest of world history has changed. At least the broad strokes.
Part of which will require looking at wind and current patterns, because while magic in this AU may be accessible anywhere, the capability to use it is carried between people, animals, plants, and other creatures in an infectious manner, by the space microbes involved. Meaning it has to physically get across oceans and continents.
(No, they’re not midi-chlorians. Don’t think I don’t see you back there waving lightsabers….)
I do know that the wave got to Eastern Europe at some point and created actual vampires, sometime before the 1380s. Likely at least a few decades before, so a pale traveler could get back the other way through the Yuan Dynasty’s territory and infect one hapless Choe Ryu-Cha. (I suspect that was very, very messy, yes. Even before he decided to help his brother the general survive an attempted assassination and rock the whole monarchy.)
So in this ‘verse Dracula as Vampire likely is a Thing, yes. But what else?
I know William Adams still made it to Japan in or around 1600, because the subject of Miura Anjin comes up at one point in the story. And the Jesuits are definitely trying to win converts in China, as per regular history. (They may have vampire hunters in their ranks, this time around.) But what else has happened? What’s changed, or not, in Europe and the New World? I need to dig around and find out.
If anyone has any pet peeves or neat bits of history between about 1266 and 1618, feel free to drop me a line!