If the idea of a weapon that grows in power with a character appeals to you, and fits within your campaign, this book is for you. Even if you are unsure on the weapon evolution mechanic, they are interesting and inspirational magic weapons for a campaign.
Legendary Weapons (a sequel to Legendary Blades) is a 25-page PDF (23-pages if you remove the credits/OGL page) for the Pathfinder RPG written by Mark Gedak and Stefen Styrsky and published by Purple Duck Games.
