Ares needs to be huge, hulking and menacing. He needs to have really broad shoulders, be looking slight down just like he's going to PWN you right there. : P
Him looking slightly haunched over ready to pounce may be a good one.
You gotta look at him and say... 'Whoa, I'm not messing witht that badass!'
If you make bases so all the gods kinda fit together that will be cool. : )
I kinda like this pose from Kratos but maybe tweaked a little: