It must be understood that there is not a single country in the entire continent that does not have at least a handful of master-level experts, meaning that for a country to survive it needs to have at least 5 experts of the same strength as Oliver.
This alone already demonstrated the strength of this vampire family, as this duchy is surrounded by 4 countries where there are powerful experts and even demigods and yet they are able to keep them at bay.
Andrew and his wives were surprised to hear this, as they never expected such monsters to exist on this small piece of land, but now everything seemed to fit together.
At first when Andrew heard that the duchy of Cannes served as a buffer zone for the surrounding countries, he imagined it would be a war-torn and dilapidated region.