"Pure bloodlines" refers to a belief or concept that determines someone's ancestry or heritage, without any mix or blending with other groups.
Full definition
Satan attempted to taint
the pure bloodline so that YOUR savior couldn't be born.
This has muddled the preservation of
a pure bloodline, as well as tarnished the Kangal's iconic image as the country's national treasure.
This isolation helped Kangals retain a strong,
pure bloodline, exemplified in their unwavering, cool disposition and streamlined appearance.
It's also said to have
the purest Bloodlines and existence.