Stalker Soul Shield pieces can only be obtained from Everdusk Stalker Jiangshi Wheel of Fate which located at Foshi Pyres in Everdusk. To use the Wheel of Fate, an item called Stalker Jiangshi's Essence which only drop from area boss Stalker Jiangshi that roam around Moonshade Cemetary. The wheel will give you soul shield pack, Locked Stalker weapons, and even costumes.