The rarity of The Undying Light is Rare, and been equipped it takes a “Bundle” slot. At this moment the item is available for trade.
The Undying Light is a skin for Omniknight. The skin was added to the game on October 26, 2017, it was created by Toasty.
The Undying Light is currently one of the most popular skins, but it is rarely seen in the game due to its high price.