To defeat the first Krulls, shoot them in the face with an arrow, then use magic to pull them forward twice, then jump on their backs and run them off the cliff. In the underground, make sure to activate all the crystals on the wall along the path, then open the door and head up the spiral staircase. When fighting on the gem, don't ride the Krulls, it takes too much time and the gem will shatter before you can finish. Just blind them and hack away. The puzzle in the next are is: red, green, yellow, red, green. And finally, on the bridges, clear the enemies until you can grab the ledge (rocks will tumble away when you can proceed) and just make a mad dash for the end, getting health from crates along the way - there are way too many enemies to actually fight.