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