"In truth, it is her power that makes these weapons truly magnificent. Her power, laced with her hatred, crashes endlessly against Odyn's spirit. The tension between those energies will forever permeate these blades..."
The keeperOdyn believed that the mortal races were too weak to protect Azeroth. He instead decided to create an army of titan-forged champions, known as the Valarjar, to protect the world. For the foremost among his Valarjar he decided to craft a pair of magnificent blades. Odyn sought out the greatest of the vrykul smiths and asked him to "focus not only on mere defense, but also on the poetry of aggression." Taking the keeper's words to heart, the smith forged perhaps the greatest weapons ever craft by a vrykul. Odyn then blessed the swords, imbuing them with his own power. Odyn then hung the swords in the Halls of Valor and told his Valarjar to prove themselves worthy of wielding them.
The first to prove himself worthy was a renowned vrykul warrior named Ingvar. While leading a raiding party, Ingvar found a cave full of creatures corrupted by the Old GodC'Thun. Ingvar and his warriors died fighting, but they slaughtered every last creature before Ingvar drew his final breath. Helya brought Ingvar's spirit to the Halls of Valor, where Odyn declared him the greatest of his Valarjar and presented him with the blades.
When Helya turned against Odyn, sealing the Halls of Valor within a separate plane, Ingvar was one of the few Valarjar outside of the halls. Without hesitation he struck back at Helya, knowing he was unlikely to win. Though he fought valiantly, he was ultimately struck down. Helya claimed his swords and kept them as a memento of her victory.
Helya began turning the vrykul spirits in her care into the undead kvaldir. In time, one of the kvaldir--a powerful warrior named Vigfus Bladewind--rose to prominence among them. In a further mockery of Odyn, Helya gave his blades to Vigfus and formed the Helarjar, tasking them with hunting down particularly powerful vrykul and taking their souls before Odyn could lay claim.
For thousands of years Vigfus and the Helarjar raided the most heroic of the vrykul. Helya even added some of her own power to Vigus's weapons, that they might more easily claim souls for her. Shortly after the Burning Legion invaded the Broken Isles, Odyn took a new champion: a mortal adventurer. Wishing this champion to wield the blades forged for this purpose, Odyn sent the warrior to Tideskorn Harbor in Stormheim to kill Vigfus Bladewind and recover them. The two fought a great battle, but in the end it seemed Odyn's champion would emerge victorious. Vigfus called out to Helya for aid, and she poured yet more of her power into the swords, but it proved insufficient; Vigfus was slain, and his blades--now empowered by both Odyn and Helya--were once more in the hands of Odyn's chosen warrior.