Konrad Curze

Konrad Curze fell to Nostramo, a sunless world of endless night, and raised himself alone in its underhive among the worst of humanity. He survived by becoming a greater terror than the murderers around him, and in time he imposed a savage order upon that world by flaying the guilty and displaying them as warnings, until Nostramo grew quiet not from virtue but from fear of the thing that hunted its darkness.

That was the whole of the lesson he carried into the Legiones Astartes, and he stamped it upon the Eighth Legion without compromise: that terror, wielded without limit, was the surest weapon a warrior could hold. Yet Curze was cursed as well as cruel, gifted with visions of the future that showed him nothing but death and doom, until he came to believe himself merely the instrument of an inevitable justice.

That certainty hollowed him and drove him toward madness. When the Heresy came he took the Eighth into rebellion, though he cared nothing for Horus's dream of empire; he sought instead to prove that the Emperor had knowingly forged him to be a monster, and would therefore have no right to condemn the monster's work. He became terror incarnate, a primarch convinced that his every atrocity was simply the future arriving on schedule.