The developers added Strap of Black Nihility to the game on May 1, 2015. This skin belongs to Night Stalker and is worn in the Legs slot. It has Mythical rarity and it is part of the Black Nihility set. Players can get this skin from Immortal Treasure I 2015 bundle.
How to get Strap of Black Nihility
Players can purchase this skin on the Steam Market.