Storm's Teeth was a colossal chainblade, too weighty for any but a Primarch to wield, and was the favoured weapon of the Primarch Rogal Dorn. It was crafted for Dorn by the weaponsmiths of the planet Inwit, before the coming of the Emperor, and its razored teeth could shred any material with ease.
In a battle between Alpharius and Dorn upon the Hydra Moon Fortress orbiting Pluto, Alpharius was able to stab Dorn with his Sarrisanata ("Pale Spear"). Dorn then grabbed the spear and held Alpharius in place before slicing Alpharius's hands from his wrists before he slashed Alpharius across the chest with the chainsword. He then stabbed him with the spear before finishing by cutting through Alpharius's skull with the chainsword.