Ryu would win for sure since you say full power, the True Dragon Sword has the power to inflict damage on demons and ghosts. The ninpo plus the soul boosting thingy (since you said full power lol) will own Dante.
Unless someone like god throws a lightning bolt at Ryu, hey he still is human but with awsome skills.
__________________ Do you define yourself? Or do others?
Its more then about power. Dante is rush in type of guy which well works for him but Ryu is a ninja and smarter and even though he is only human he defeats demons while Dante is half demon which gives him a leg up in defeating them and not being able to die. Since he was shot in the head andhad sickles all stabbed into him. Ryu couldn't kill him but he could outthink him and win. Ryu has the power along with skill and brains which is why I choose the ninja.
__________________ If you try something stupid, and it works it ain't stupid.
Dante can be killed, just that not by normal means. Ryu has the True dragon sword which can hurt demons and ghosts and all the other crap that isn't human. Dante is reckless and just tries to go for the kill right away, but Ryu is a ninja who is patient and smart and knows his way out of a fight even in massive odds. If your talking about a fight Ryu would win, but if its fight to the death than thats another thing.
__________________ Do you define yourself? Or do others?
How is Dante reckless? He's an experince hunter, a great sword master, know's MAs, and it seem's he knows how to use every weapon that he picks up with no problem. Ryu is a skilled fighter, but he's facing off against a skilled half demon with a healing factor and other powers. Dante wins.
Dante being able to heal at a fast rate gives him a huge advantage since Ryu will be slowing down longer the last. And Ryu isn't able to heal from critical wounds, Dante can. Dante win this match, without transforming too.
PS : I wouldnt say that ryu is faster than Dante...Dante being able to run down a giant tower, throw his sword, boost it's speed with a bullet, outrun it and all. hehehe.
The heaviest weapon Ryu has ever mastered is that giant gold and black sword, that nothing compared to what Dante has mastered, he "mastered" fighting with a motorcycle and that in a few seconds.