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