The Feeding flaw “Methuselah’s Thirst” on page 181 says “Your hunger can only be fully slaked by the blood of supernatural creatures…otherwise, it remains constantly at a minimum of 1.”
Does this replace the usual rule where the only way to “fully slake” hunger is to drain and kill a human being? (p.212) Do they stack? If so, is your hunger dice floor at 2 until you find someone supernatural to drink from? Or do you have to drain a supernatural creature to death to lose your last hunger die?