Board Thread:Help/@comment-2604:3D08:3480:5E00:2CDE:2F71:8A:B860-20190925232438/@comment-27794543-20190926014648

You spell it the same way you did except as one word, i.e. "Nightblood".

Nightblood refers to three things:
 * A serum created by Becca that genetically alters the receiver to have a higher resistance to radiation and that has an unintended side effect of turning receiver's blood black.
 * The genetic trait caused by Becca's serum.
 * The people with the genetic trait caused by Becca's serum - either by being injected by the serum or by inheriting it from someone who has.

So the following statements are all correct:
 * Becca injected herself with Nightblood.
 * Becca has Nightblood.
 * Becca is a Nightblood.