Known spawn locations (click for map image -- PH "a soul taker") for your "ethernere.txt" map file (note for all known Ethernere Tainted West Karana named spawn locations, see this quest entry):
P 4495.1519, 1328.8987, -455.6906, 127, 0, 0, 1, Soul_Sifter
P 4450.5801, 1508.8400, -455.3400, 127, 0, 0, 1, Soul_Sifter_(roam)