This sword can be found in the werewolf cave while escorting Brigida during Testimone della corona. It is added in the Enhanced Edition update. Along with Spada del vran dimenticato, Caerme, and Lutto, it is one of the best steel swords in the game.
Notes
On the Xbox version, a glitch may occur where the sword does not spawn in the werewolf cave. There is no currently known way to fix this glitch.