Comments of chapter undefined of Between The Will Of Fire & Hate

What meaning does Oketsu (悪血) have? 血 (ketsu) means blood, that much I know, but which meaning does your 悪 (bad/vice/ rascal/false/evil/wrong) have? Impure Blood? Or were you thinking of the state of blood stagnation in oriental medicine, Oketsu? Ah, sorry, I'm just really interested in the meaning behind names.