So what happened to the Slavs?
Assuming you mean Slavs in the Balkans, some (mostly converts and those who intermarried) assimilated into the Xasar, Bolghar, or Turkic culture, others assimilated into Roman culture, and many remain living in the Balkans, where up until recently they were under a separate legal system as detailed in my earlier posts on the subject.
Also, I just want to clarify: I'm more than happy answering questions, and I love talking about this world, but in case you haven't read the timeline yet, it is meant to be read in a linear order, starting with the first thread. This thread isn't meant to be a standalone story, although I hope to some degree it works as such.
There's a link to the first thread in the first post of this thread. I will always do my best to provide recaps and in my posts I try to reference back to other events, because I absolutely don't expect people to remember events that I wrote about four years ago with perfect clarity, but at the end of the day it's gonna be a bit confusing if you don't at least vaguely remember the backstory of how we got here.