This instance is the domain of Countess Satrinah, a valkyrie with unnatural presence and leadership who recruited smaller barbarian tribes to form a horrible cult with depraved intentions. Together they formed the Cult of Satrinah. They're history is best described by Haijakt, a barbarian historian in Everfrost. Below is an exert from the dialogue with him:
"...the cult [raided the other tribes and] captured many barbarians for her. Satrinah killed the victims and bathed in their blood, believing that it kept her looking young and beautiful. This went on for many years and the cult grew stronger and bolder in their kidnappings. However, Satrinah slowly began to realize that the blood of the barbarians was having little effect on the quality of her skin. Obviously such blood was deficient and better blood was required."
"When cultists returned one day with valkyrie captives among the 'lesser' barbarians, Satrinah saw an opportunity. The valkyries were consumed in the same beastly fashion as the anguished barabrians who preceded them. During the frenzy, the drained bodies were carelessly discarded and later discovered by the valkyries. Up until this point, they did not concern themselves with the demented actions of their kin against the barbarians."
"However, when they saw what Satrinah did to her own people, they could not stand idly by any longer. Their campaign was brutal and effective and they quickly killed or routed most the cultists. When it came to dealing with Satrinah, however, they knew that death would be too easy a fate for someone so deranged. So Satrinah was damned to a death while alive. Sealed into a tomb of ice and never let out, she died just a year later. The surviving barbarians and the valkyries made a pact that day to not let a horrible event [like that of Countess Satrinah] happen again."