From their website:
The sadism of the Satyxis is a legend among those who sail the waters of the Broken Coast. But even among the depraved Satyxis are a few whose appetites for atrocity are greater than their sisters. The Blood Witches work their dark magic through blighted ritual blades known as Blood Razors. Those who fall to a Blood Witch’s knife may be burst into a lingering crimson mist or have their vitality turned against their fellows in a lash of psychical death energy.