What do Del Toro and Hogan mean when they say a peculiar brand or blood alchemy?

When Del Toro and Hogan refer to a "peculiar brand of blood alchemy," they are highlighting the transformative and often mystical relationship between blood and identity, culture, or power. This concept suggests that blood serves as a medium through which profound changes can occur, whether in personal or societal contexts, often intertwining themes of sacrifice, rebirth, and the merging of different heritages. It implies that blood is not just a biological substance but also a symbol of deeper connections and transformations within narratives.