[Law wants to complain that there's no reason dragon blood would be spicy for a bunch of nerdy science reasons but it's not relevant so he just quashes that urge down like he does the vast majority of his feelings.]

So you're saying only consuming non-human blood would keep you alive but not at peak health.
[He's got so many theories, most of which could be tested if he could get some of Diva's blood, but that seems like a pretty big, intrusive ask even to him.]

I suppose there's some sort of component in human blood that your body doesn't produce, some sort of antigen if I had to guess. Though, if that were the case, it would be more effective and efficient to just inject into your bloodstream.