The rarity of Cauldron of Summons is Rare. At this moment the item is available for trade.
Cauldron of Summons is a skin for Shadow Shaman. The skin was added to the game on January 24, 2014, it was created by SebastianBastian.
Cauldron of Summons has been recently added to the game, which makes it rather popular with the game community.