You got the blonde Berber tribesmen from the mass demand for Slavic concubines. Most male slaves were either castrated or soldiers. That’s why kids of “captive slaves” were allowed mobility, they had fathers of prominence. Just like how mulattos had higher mobility in the Americas because most were born to a male of prominence. However, the “mixed” blacks of today are not considered white until they commit transgressions, while there are practically zero ethnically Slavic people’s in Asia or Africa.