if you're talking about the giant, then look at the sides of the arena. there are 2 places where the prince can wall run, and go to a higher platform, then to another. jump to the beast, then the rest are like speed kills. (you must go for the eyes) then hit the legs, and when he's down, climb to the back, then again, it's like a speed kill.

note: always wait for the dagger to flare before you attack