Knull was an eldritch god of darkness and the creator of the symbiotes. While residing in the primordial void that existed between the Sixth and Seventh Cosmoses,[20] he was awakened when the Celestials invaded his kingdom of darkness with light. Knull was chosen by the Celestials to serve as the King in Black but he rejected the responsibility.[21] With the first symbiote in the form of a sword, he decapitated one of them and used its severed head's divine power to refine the blade,[12] linking both Knull and the Necrosword to the fallen cosmic god.[22] Waging war against the Light to return the universe to the Void, Knull became a legendary figure of divine terror but eventually found himself stranded on a nameless planet after an inhabitant stole his blade and unwittingly followed in his footsteps. He experimented with his powers and discovered he could bond his living abyss with "lesser creatures" in the form of amorphous parasites that he could control.
Establishing himself as the nexus of the Hive he created, Knull proceeded to conquer worlds and form a fleet of Symbiote Dragons. When two of his dragons arrived on Earth, the young God of Thunder Thor Odinson struck down one of them and severed Knull's connection to all of the other Symbiote Dragons, who dissipated into countless individual symbiotes, while the other would seemingly be killed by Thor in a mid-air battle, its body plummeting to the depths of the North Sea. Merging with the closest hosts they could find, the Hive was now infected with concepts of honor and nobility, so the symbiotes turned on Knull and trapped him at the core of the throneworld, rebranding themselves "Klyntar" out of their word for "cage."