You've suddenly become the heir to the role of Elemental Guardian Spirit, and that's going to mean becoming a true master of Fire, Water, Earth, and Wind. Needless to mention, there are enemies that seek to stop you from doing so, which is why you'll be armed with Katana Blades, Twin Blades, Bladed Spears, Throwing Spikes, Shuriken Stars, and Smoke Bombs. The dark ninja Akunin is your true foe, and you'll spend 16 single-player levels trying to defeat him and tackle the elements.