The blood of the Virgin Mary is a hidden item of the side task "Tianya Cuisine". In the deepest part of the maze behind the archaeologist's home (the imperial capital), you can find the synthetic formula, and then synthesize it in the refining furnace of the Naga witch base.

Ps: Get the formula of the blood of the Virgin Mary, and then hand over the task of Tianya cuisine, and you can get: Really gluttonous.

Finally, I wish you a happy game.