Yeah but Artos needs development. If it were that simple you would lose the air of an impossible opponent. So I'm gonna have him struggle and show his cunning and stubborn side. 

Go for the faceplate. Drown him by flooding his facial visor with near freezing cold water and smack his blades on the joints of the armor. Hard as steel it may be, but flexible parts are always the Achilles heel. Should theoretically still be able to force him to a knee or numb the elbows.
Maybe even try forcing the temperature to impossible temperature and recklessly endanger himself to gain a minor advantage.

Sounds like fun!