The rarity of Burning Nightmare is Rare, and been equipped it takes a “Bundle” slot. At this moment the item is available for trade.
Burning Nightmare is a skin for Chaos Knight. The skin was added to the game on September 14, 2016, it was created by Attasik.
Burning Nightmare is currently one of the most popular skins, but it is rarely seen in the game due to its high price.