Hmmm, I think he was less powerful, since it was stated that Sauron at the end of the Second Age was more powerful than Morgoth at the end of the First. If Sauron was more powerful in the Third Age it would've been stated like this: Sauron at the end of the Third Age was more powerful than Morgoth at the end of the First.
Besides, the forces opposing Sauron at the end of the Second Age were far more powerful than the forces opposing him at the end of the Third. The remnants of Numenor (still powerful by their own right) and the Elven kingdoms of Eriador, unified in the Last Alliance, were far more powerful than the power of a declining Gondor and Rohan at the end of the Third Age.
__________________
'I am the Elder king: Melkor, first and mightiest of all the Valar, who was before the world, and made it. The shadow of my purpose lies upon Arda, and all that is in it bends slowly and surely to my will.'
|