^ They are definitely not the same being. Even The Word is just a page in Destiny's book:
Anyway, using the Endless in versus threads is pointless, given what they represent/embody. They simply cannot be quantified the same way as 'regular' characters.
Take Destiny, for example: his entire purpose as a conceptual entity is to sit back and watch 'the plan' unfold in his book -- to bear witness, as it were. He cannot intervene in any situation unless his book specifies such... It's not like Destiny is out there fighting bad guys and racking up uber feats or w/e.
That being said, there is no possible way that The Word can destroy Destiny, and it's unlikely that Destiny would ever act against The Word.... So stalemate, I guess.