The necroswords were obsidian swords that were used by Hela, especially during Asgard's era of expansion of the Nine Realms. However, Odin, Hela's father and the king of Asgard, later imprisoned his daughter in Hel, as he saw Hela's ambition and lust for power as a threat to remaining peace and stability throughout the Nine Realms. During the battle between the Valkyries and Hela, she summoned and used many necroswords to subdue and kill all of her attackers, except for Brunnhilde.
Thousands of years later, in 2017, Hela would eventually be released from Hel after her father's death. After Odin passed away in Norway, Hela appeared, coming out of a portal. There, she was confronted by her two brothers, Thor and Loki, who insisted on making a peace offering. However, Hela later attacked her brothers and eventually made it to Asgard via Bifrost Bridge. At Asgard, she used her necroswords to massacre and kill all the Einherjar.
During the final battle between Hela and the Revengers, Hela again used her necroswords to attack her enemies. However, as Surtur, who was reborn with the power of the Eternal Flame, fulfilled the prophecy of Ragnarök, destroying Hela, Asgard, and the rest of its inhabitants.
- The necroswords are based an amalgamation of two different weapons from the comics: the Nightsword Hela's cursed sword that she was able to summon at any time; and the All-Black, the first symbiote who manifested his form into a powerful sword with dark properties, created by Knull and previously wielded by Gorr the God Butcher, both of whom used it to slay gods across the cosmos.