DM cannot lose here.
Here is his defense.
He doesn't need a body (avatar) at all to exist and can reform one at will. He can multiple himself many times over and grow in size.
He can become intangible and not even be touched by Surfer.
His reflexes are probably infinite since he is always seeing through time and also he has witness events on a quantum level so fast that it can be said not to occurred at all (planck time?).
As far as offense.
He could probably teleport Surfer's head off.
He can multiply himself a million times and fight Surfer. For each body Surfer destroys DM creates a hundred more. He can grow to giant portions as well.