The developers added Arms of the Lost Vigil to the game on May 7, 2019. The rarity of this skin is Rare and it is part of the Relics of the Lost Vigil. Designed for Sven. Worn in the Arms slot. This skin could be obtained from the The International 2019 Battle Pass.
How to get Arms of the Lost Vigil
Available after purchasing The International 2019 Battle Pass.