Well, first, consider their backgrounds. Peter Parker comes from a relatively ordinary life in New York (aside from being Spider - Man), while Valkyrie is an Asgardian warrior with a long and complex history. In a fanfiction, you could bring them together by having Peter accidentally enter Asgard or Valkyrie visit Earth. Their different outlooks on life would create some interesting conflicts at first. But as they get to know each other, they could start to respect and incorporate each other's values. For instance, Valkyrie could admire Peter's tenacity and self - sacrifice, and Peter could be in awe of Valkyrie's courage and combat expertise. This gradual change in their relationship can be the heart of a well - written fanfiction that blends their characters effectively.
One way to blend their characters is through their shared sense of justice. Peter is always looking out for the little guy in New York, and Valkyrie has a strong sense of duty in Asgard. A fanfiction could start with them meeting due to a common enemy who is causing trouble in both realms. They would then learn from each other's ways of dealing with threats. Peter could learn about Asgardian honor from Valkyrie, and Valkyrie could pick up on Peter's quick - witted improvisation skills. This would create a more dynamic and interesting relationship between the two characters in the story.