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