Ninja Gaiden II/Chapter 5: The Aqua Capital

"Elizébet's whereabouts remain unknown, but her twisted plans continue to unfold as she unleashes the fearsome power of the Demon Statue. Wherever she goes, its power awakens one of the Four Greater Fiends from his long slumber. The roar of Greater Fiend Volf, Ruler of Storms, echoes throughout the beautiful city of canals, transforming a Gothic Castle into an evil fortress"

After the chapter begins, head forward. You will be attacked by several Purple Ninjas and Claw Ninjas. Head forward. To the right of the stairs ahead is a Muramasa Statue. If you have a good amount of Yellow Essence, I recommend saving it because you are about to get a new weapon. Head up the stairs and to the left, down some stairs. You will be attacked by some Werewolves. Their grab attack is pretty damaging, so keep them at a distance. At the bottom of the stairs is a corpse containing a Kusari-gama. Head across the water to the opposite platform and follow this platform to the end. Here is a chest containing Red Ki Essences. Turn right and run across the water for Crystal Skull (#10) and a 20 point achievement that goes with it. Head back to where you descended the stairs. On the way back, you will be attacked by some Water Scorpions. Dispatch them with your shiny new Kusari-gama.

When you reach the bridge head across and down into the market area for another skirmish with a larger group of Werewolves.