Was Sauron a Balrog?

[alatar]

Originally Posted by Nerwen

Uh... yeah... whatever you say...

Sorry; must have been a little nutty at that moment.

What I obviously meant to write was that Balrogs maintain the same shape/form/appearance whether they're whipping Ungoliant away or fighting Gandalf on the Bridge. Even when wet, Balrogs do not radically change shape. Sauron, on the other hand, had taken many different shapes - some fair (Annatar) and others foul (wolf, Eye, etc).

Clearly horses of different colours.

The Encyclopedia of Arda has Arien as a Maiar of Vána.