The Crimson Curse, or Evils Awakening, is a curse prophesied by Eltibald. He prophesied that once the moon turns a crimson hue, monsters - those previously hidden to mankind - would emerge to feast on flesh and blood. However he passed away before he could complete his manuscript descriping the event, and his students saw his last works as ravings of a madman. Therefore, they decided to hide them from public view.
Eltibald derived his prophesies not only from observations of celestial bodies, but also from inscriptions from the Wozgor and Dauk people. He learned of the Crimson Curse from the Svalblod cult on Skellige.
Intelligent creatures such as Higher Vampires, Sylvans and knockers knew about the curse a long time before the humans, and have been anticipating it, as they saw it as a oppotunity to settle their grudges against humankind. [1]