The rarity of Blossoming Harmony is Rare, and been equipped it takes a “Bundle” slot. At this moment the item is available for trade.
Blossoming Harmony is a skin for Storm Spirit. The skin was added to the game on September 15, 2015, it was created by Toasty.
Blossoming Harmony has been recently added to the game, which makes it rather popular with the game community.