What if at some point after the Rebellion, Eyeball personally returned to Earth to finish Rose Quartz, but was unable to locate her, and during her journey, she came across Scandinavia, where the inhabitants mistook her for an agent of Odin (while others mistook her for an incarnation of Odin) and she used this naivety to her advantage? Here's what happens: She convinces the Norse people to bring her all their youth so she can train them in combat, claiming it's for a great battle for the fate of the world (thus, the origin of the story of Ragnarok) and told the trainees that once they reached adulthood, they were to head out into the world and raid, pillage, and fight, thus triggering the beginning of the Viking Age. Basically, she hoped to use them to defeat Rose Quartz one day, however, by the time she returned to Earth thousands of years later, the Viking Age had come to an end.