when does this happen, year wise, or in relation to us, and when did it start , i.e when did the artifact take hold of Auril when her sister was away, the black ten facetted gem?Aurilandür and Auril are one and the same. Long before humans started venerating the Frostmaiden, she was known as the Frost Sprite Queen, a (mostly) benevolent winter fey with a seat on the Court of Stars. She was latter corrupted by a malign artifact, warred with her sister the Summer Queen, and was banished from the Feywild. Thereafter her name was stricken and she was referred to only as the Queen of Air and Darkness. At this time she garnered a human following and joined Talos-who-was-Gruumsh as one of the Gods of Fury. With the aid of Silvanus, the dark artifact’s hold over Auril was shattered during the Stormstar Requiem, and the Aurilandür of old has once again begun to peak through Auril’s icy, malevolent veneer
What Azmodeth has been based on, was finding a records of Auril growing up, snooping around the High temple of ice as a child. Not being fit as an Aurilite, they refused to keep her and gave her off to some wizard to use to fill in some debts.