I don't think it's the "no blood" issue that would give Raziel the victory. Kain can't draw blood unless his enemy is stunned, and Raziel can't devour a soul until the enemy is dead.

I think Raziel would win because his abilities are a lot more practical to this battle. Being able to transform into a wolf or mist is nice when you're skulking through a canyon, or trying to cross a swamp, but in the midst of battle, Kain is going to find more use in his spells and weaponry. Raziel can use pretty much everything he has to his advantage in this fight, and Kain has a number of abilities that will go unused. It is because of this lack of skill maximization that I think Raziel will come out on top. Plus, he's beaten Kain twice before, he just hasn't killed him.