Do you want to compare Sif with Duplicate Girl? Discover the powers, weakness & weapons of Sif and Duplicate Girl from Sif Biography and Duplicate Girl Biography. Find out all about Sif and Duplicate Girl.# Check out how is Sif unique and distinct from Duplicate Girl. Discover their love interest, sidekicks, family tree and the movies and games list in which Sif and Duplicate Girl have appeared. Find out everything about them here!