Here's the move Khuutra was alluding to: http://xbox360.ign.com/dor/objects/686645/ninja-gaiden-ii/images/fable-2-20080513084938313.html?page=mediaFull
I've gotta go with Ryu simply based on their fighting styles. Kratos is more powerful and he has some pretty nifty items like the wings and boots. However, his fighting style is totally offensive and he's a pretty brutish guy that lacks speed and focuses on straight forward attack. Even the boots take time to become effective. Ryu is a master ninja who's entire training is based around evasion and silent but deadly attack. This alone puts Kratos at a massive disadvantage. Add to that a plethora of different types of weapons (big and small, fast and slow, far and close), crazy magic spells (as above) that make him invincible when cast, and the backing of the CIA (:P), Ryu's got this fight in the bag.
As for the difficulty of Ninja Gaiden series (speaking from experience with the Xbox versions), I had more trouble with NG2 on Normal than I'm having with GOW 3 on Titan.
