The rarity of Blade of the Volatile Firmament is Rare. At this moment the item is available for trade.
Blade of the Volatile Firmament is a skin for Spectre. The skin was added to the game on August 14, 2014, it was created by GreyskyS.
Blade of the Volatile Firmament has been recently added to the game, which makes it rather popular with the game community.