Hi Kosmaz!
This looks really interesting. Definitely fits with the Baltic setting, it’s just a bit to the South! It would kind of fit with some of our ‘Monsterberg’ series of modules which take place shortly after the fall of Constantinople.
This books looks great, I’m tempted to get it now…
https://www.drivethrurpg.com/product/229016/Mythic-Constantinople–TDM230
Would love to learn more about your campaign.