The Newbloods are humans, always of the Deris bloodline, that have not yet entered Metabolism and become a Dierish (See http://characterbio.wikia.com/wiki/The_Dierish). They do not know that they are a Newblood until they actually enter metabolism, and this can occur at any age between 17-27. The stages include the skin dripping off in random positions, and the human affected to become extremely sensitive. Once through the metabolism, which can take weeks-months to get through, the former human is now a fully-fledged Dierish, with all the positive (and negative) traits that brings.