The Røkkva was a primordial antilife entity spawned near the beginning of the universe, roaming the cosmos and mindlessly destroying or corrupting everything it came across. As life spread throughout the universe, the Røkkva grew increasingly powerful and destructive. Eventually, a king named Øde sought to claim the Røkkva's power for himself and bonded to it, becoming one of the most powerful beings in the Ten Realms. However, the Røkkva corrupted Øde, twisting him into an evil shadow of his former self and blackening his body into a soulless husk that was neither alive nor truly dead. Øde's subjects eventually rebelled against him and slew him with a weapon crafted from the white wood of Fiererheim - the one material capable of purging the Røkkva.
The Røkkva was imprisoned in a tomb deep in the Barren Mountains of Jotunheim, the entrance sealed with ancient magics deliberately lost to time. Øde's corpse was buried nearby, and the subsequent All-Fathers of Asgard were charged with ensuring that neither was disturbed.
Untold eons later, Tyr Odinson learned of the Røkkva's existence and sought to claim it for himself. Unable to break the seal on his own, he stole Øde's corpse and attempted to resurrect him with the sap of Yggdrasill, intending for the new Valkyrie's Undrjarn to manifest a weapon made of white wood in order to kill Øde, which Tyr would then steal and use to break the seal. Tyr's plan backfired when Yggdrasil's sap failed to resurrect Øde - whose soul had been consumed by the Røkkva - and instead caused the eldritch darkness festering inside him to metastasize into a horde of life-draining monsters.
Thor Odinson, Tyr's younger brother and All-Father of Asgard, attempted to destroy Øde's corpse with Mjolnir but was infected by the Røkkva. Manifesting a spear made of white wood, Valkyrie was able to destroy Øde's corpse, but was left too exhausted by her battle with the corrupted Thor to stop Tyr from stealing Undrjarn.
Returning to Jotunheim, Tyr and Thor broke the seal on the Røkkva despite Loki attempting to intervene. The Røkkva submitted to Tyr's control as long as he possessed the white wood spear, but quickly began to eat away at his mind and soul as it once had Øde.
Tyr then used the Røkkva to attack Asgard and infect the Asgardians. Jane went toe-to-toe against Tyr, but he stabbed her with Undrjarn. This however, allowed Jane to take back her weapon, becoming Valkyrie again and using Asgard's light to weaken the Røkkva. After Tyr's defeat, Jane brought the Røkkva back to its prison. Feeling sorrow for it, Jane tried to talk to the Røkkva before locking it up, but received no response.
The Røkkva possesses no mind of its own, seeking out and destroying all life that it comes across.
Antilife: The Røkkva is a mystical entity manifested from antilife, and as such its touch is invariably fatal to mortal beings - infecting and consuming their bodies like cancer. Only deities are capable of withstanding it, though they will be corrupted by it into blackened, soulless, evil versions of themselves. Those fully corrupted by the Røkkva become effectively invincible, unable to be harmed save by weapons fashioned from the sacred white wood of Fiererheim. The Røkkva can create tendrils of antilife, and can also generate monstrous offshoots to hunt down prey.
White Wood of Fiererheim: The only known weakness of the Røkkva is the now long-extinct white wood of Fiererheim, which was capable of purging its corruption and slaying those imbued with its power.
- The Røkkva bears many similarities to the Symbiotes, being a primordial entity of antilife dating back to the beginning of the universe; and being capable of both empowering hosts - with divine entities being the intended victims, corrupting them, and draining their vitality to the point of death. However, it is presently unknown if the Røkkva is a creation of Knull or an independent manifestation of the primordial void.