And this is by chance a question-reference-riddle about girls? Monthly type?
Don't minus for my guess. .
Urgently catch the person from whom 20 liters of blood flows (I believe, with such and such enviable body resources, he is still alive) and hand him over to the nearest scientific and medical institution. For such an amazing find, boldly demand, if not money, then at least worldwide recognition. And be proud of your contribution to science, because it is something truly unique and urgently needs to be studied.