From the prophecy: as the New Gods fall from the Hallows Above, Kudamat will slay them with his stone sickle that their blood will flood the Mortal Realm. In this sanguine tide, Kudamat and the new generation of colossi will destroy the creatures of the Mortal Realm and make room for abhorrent creations to repopulate the land, sea, and sky.
Source · Drylands History