The blood isn’t entirely blood. There wasn’t a ton of the original blood left in the hands of the cult, so this is heavily diluted and I believe it is poisonous. Possibly even mostly synthetic.
But rest assured there are elements of the blood of an ancient space bug at play, here.
I also just like the intensity of “I WILL DRINK THE BLOOD.” It was a line that stood out to me when I was scripting and I think it lands well, here.