It is the strongest non-throwable weapon (except Ice Rapier). Also known as the Cyclopmania Sword, Cyc Sword and Godslayer. You can see that this swords hilt form is made of Rapier and Longsword hilt forms.
The ingame legend is as follows:
Many many years ago the evil god Brog enslaved cyclopes to smith weapons for his perilous armies. In secrecy, the cyclopsmiths created this powerful weapon in order to commit mutiny against their captor. They failed at the task of slaying Brog, however Brog was heavily wounded. Filled with unspeakable rage he cast the sword down into the lands of Tibia to be lost forever. While buried in Brog's flesh, it became covered with his horrible blood, which hardened the blade and enchanted the 'Godslayer' with unmatched power. However, a dark curse has been cast upon the blade causing it's owner to become stricken with awesome madness and horrible luck. It is said nothing good can come to he who posesses the mystical blade. One of the known owners is Rafos from Antica. This sword is not available from any monster or quest so far.