Complex sentence: Only the shtriga herself could cure those she had drained (often by spitting in their mouths), and those who were not cured inevitably sickened and died.
Split into simpler sentences: Only the shtriga herself could cure those she had drained. According to legend, only the shtriga herself could cure those she had drained (often by spitting in their mouths), and those who were not cured inevitably sickened and died.