The more I think about it, the more I find it hilarious. Ares in GOW was so overpowered that no other gods were allowed to fight him other than Zeus, Poseidon, and Hades. And that was before he had Pandora's box in the palm of his hand. He had someone who was created for the singular purpose of killing the unkillable under his thumb. And he lost because he did the one thing he was advised not to do which was reveal to Kratos that he was the one who put the wife and kid into the shrine house, knowing Kratos wouldn't be able to stop himself in time.
He could have brought Olympus to its knees. And all he had to do was pretend to ignorance.
There is a head canon that's floating around the internet in which Ares is the reason the Greek gods don't interfere with the affairs of mortals anymore. He became so strong due to the blood that mortals spilled in his name, that he was able to break the other gods and force them into submission.
That could have been him if he had just kept his mouth shut XD