They do both sound good...I think, those with copper in their blood can do a certain type of magic, which is illegal unless you are born into certain families/crafts sort of thing...so it's a name for a caste of people really I think, who have the wrong blood, from the excerpt up for critique it seems they get killed...so anything that could cover that, I think Greek probably counts as an option on Latin, so I'll expand it to Latin, Greek or Romance languages...a couple of people have suggested, and put up their lack of Latin, so only as a guess "malasangue", "essangue" "insangue", "unsangue" and "utsangue"...but the discussion is still trying for more of a wrong blood, not of the correct blood etc

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