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