Chapter 3: Skies of Vengeance
Hayabusa's got a new look and a new mission: get back the Dark Dragon Sword by any means necessary. The level structures themselves are also going to change. From this point on, Ninja Gaiden's stage layouts become considerably more complex, with multiple doors, keys and various switches and devices you'll need to fiddle with to proceed. You'll also find yourself backtracking to previously visited areas much more frequently.
Upon starting the level, you'll find yourself in a room with a dragon statue. If you go outside, you'll see a hallway with several other interconnected rooms, along with some locked doors at the end. Investigate all of the rooms to find a few restorative items to add to your inventory, along with a map of the airship. Immediately after collecting the map, you'll be interrupted by a team of armored soldiers breaking in through the windows. The white-armor soldiers aren't too tough, but the black troopers have a strong guard that can be hard to break. Both types of soldiers are able to use a damaging grab attack if you remain motionless at close range, so don't just sit there guarding for too long.
Once you administer the requisite beatdown, you'll find a glowing item on the floor. Pick it up to get a key to the locked doors at the end of the hallway. Unfortunately, said hallway is now infested with more troops. Take them out as you did before and go through the doors using your new key.
There are more soldiers waiting in the hallway, including a few more of the black-armored toughguys. Once you deal with them, there are several paths open to you. You'll probably want to go down the nearby stairs first. On the left side of the room from the entrance, you'll find a spiral stairwell leading down to a Muramasa shop. You'll have the option to upgrade your Dragon Sword now for 2000 essence and we highly suggest you do so - it will make your life considerably easier. (There's also the Izuna Drop technique available, which is also a very wise purchase.) To the right, there's a staircase leading to another dragon statue and a few locked doors. Make a note of this, you'll be using them later.
There's another set of locked doors across the room from where you entered, but there are two small passageways located to the left and right of it. Go to the left passageway first to find a dead-end room with two items: A chest containing a Life of the Gods and the first Golden Scarab. Collecting Scarabs is an optional pursuit that can net you some rare, exclusive bonus items from Muramasa. (In fact, you should probably go back to visit the store and give him the first Scarab. He'll give you another Life of the Gods in exchange.)
After doing that, take the right passage and continue on through the next set of doors you'll encounter in the room following. You'll wind up in a bunker area fighting more troops. This can be a bit difficult, since the fighting space is very small and the enemies have some long-range weapons to aim at you. When that's all said and done, you can exit out into a small hallway. Unlock the double doors that lead to the main cabin for later, then backtrack and enter the small door you saw across from you earlier. In here is a note, another Golden Scarab and a map of Tairon. Pocket all of them and then take the elevator down to an area with some more troopers to trounce. You'll get a lovely new ID card for your troubles. Now run all the way to the other end of the control deck to find another elevator, this one going up. Don't hop on it just yet - instead, go into the nearby room to find a chest with the Tiger Fang and Dragon Claw katanas! Equip them if you like, they're quite fun to chop with. Now you can pop up the elevator to reach another floor of the ship. Enter the nearby door to find a smallish room with a few troopers. Dispose of them and head out the other exit - you'll wind up back in the room with the dragon statue you saw just a moment ago.