From the "Legion: Warrior Artifact Review" official blog:
- In ages past, the titanic watcher Keeper Odyn betrayed the sorceress Helya, killing her and twisted her spirit into a spectral Val'kyr. He forged this pair of swords for the mightiest of his storm-forged Valarjar, but Helya stole the swords and infused them with a portion of her rage. She then gave them to her own champion, who used them to hunt the greatest of heroes and drag their souls away to serve in Helheim.
Adventure Guide Edit
Attaching herself to the Naglfar, Helya launches an all-out assault of the vessel from a distance. Defeating Helya's Tentacles wounds her, and after reaching 50% remaining health, Helya submerges under the waves. During that time, she continues to barrage the Naglfar with her tentacles. After 15 sec, Helya rips the front of the Naglfar in half and combats players directly, periodically retreating to the waves for the remainder of the encounter.
Connection to the kvaldir Edit
The kvaldir appear to be cursed souls of the vrykul that serve Helya in gathering more souls of the unworthy. Her finest kvaldir are known as the Helarjar and are tasked with gathering the souls of vrykul champions.
Helya and the kvaldir, servants of Neptulon? Edit
It seems possible that the kvaldir worship Neptulon. Their conquest of Vashj'ir hindered the naga from summoning their faceless one allies to aid them in overthrowing the Tidehunter. The kvaldir refer to Neptulon by name in N  Final Judgement. While there are naga that do worship Neptulon, like Skar'this the Heretic, many of them (as in Vashj'ir) do not and worship Azshara. Also, with the revelation that the kvaldir being the harbingers of the fallen val'kyr Helya, it also may suggest that Helya herself might have turned to Neptulon, who was one of the Elemental Lords serving the Black Empire in an act of spite against the titanic watcher Odyn.