There are four parts to this episode, making it one of the lengthiest in the game. As usual, bring Mika tickets for reviving. It also helps to upgrade "Healing" from the Special Skills list ahead of time (the max is Level 3), so that you can get to a safe spot temporarily and hold LB to trade Blood for Health. Doing this helps you avoid wasting Mika tickets, and helps a lot in the boss battle as well.
Another tip is to get Guard Crush from the Special Skills menu also. This lets you hold "Y" for a brief time, then release, to break enemies guards. This is handy against this boss's final stage.
Part 1 --
The mission begins along a path where your only option is to keep moving forward to the end. You'll be ambushed at the end (after breaking a statue that's sitting there on the ground), and encounter the first "ninja" Wires. After the battle, a scroll will appear in front of the gate, telling you to find 5 more scrolls. The gate will open.
Part 2 --
This is an open area, so you can go in different directions. That makes it a little difficult to describe where the five scrolls are to found. Each one is protected by a ninja, and to start the battle, you have to locate a small statue and hit or shoot it. During each of the five battles, gray smoke will block the exits, forcing you to kill all enemies (even if you defeat the ninja first and take the scroll).
There are 3 Scarlett locations to find there, which I've seen described in a different guide. Basically, you shoot an eye-thing floating over a waterfall to explode it and stop the water to get one, another needs the "drill" upgrade on the other side of a house where there's a rock (bust the goldish tree), and the last is after getting all five scrolls and entering the opened gate, immediately go left before walking the long path.
The statues to break are as follows:
One is under what may be the first arched bridge you cross. It's where the "samurai" appears. After defeating him, get to a good vantage where you can see under the bridge, and shoot the statue. Fight the ninja, get the scroll.
Another is on kind of an island with just the one exit back. There are bushes to slice through, which hide the statue you need to break.
One is on the roof of a house you can get to by going through an open gate in a wooden fence. It's the same area where a rock is behind the house that leads to the "tree orchard" where a Scarlett location can be found.
There is another hidden behind grass, among a cluster of rocks and stuff. You can get to it by finding a small island with two arched bridges -- one on either side. On one of the other two sides is a small cluster of rocks, and on the other, the larger cluster where the statue can be shot. It's just behind the clump of grass, and should be visible when you look. If in doubt, remember that Musselback will "flash" or vibrate when near one.
The fifth statue is on the ceiling of an open-walled gazebo, near where you first came into the area from the initial long path. Just walk in and look up. In this location, you will face two of those spiked-club-wielding large brutes, in addition to the ninja. So be prepared.
Once you obtain all five and the path opens by defeating the enemies, go back to the area of the house near the open gate. This time, another gate is open to the right of it (don't go into the courtyard where the house is). This leads to...
Part 3 --
You're riding on a motorcycle being driven by Vivienne, fighting the boss who's riding on a tiger. The path is kind of on a loop that repeats, and there is a left side and a right side. The game explains how to switch sides, by pressing A and moving the left stick in the direction. You'll need to do this to avoid obstacles along the way, like cars that jump out at you, barrels, and spiked obstructions. It's OK if the boss is there on the other side. You'll simply switch places.
This can be fairly difficult on Hard or especially Very Hard mode, since you take damage a lot easier. You have to keep your eyes on the path so you can switch sides as needed, but also watch the boss so you're prepared to block with B as soon as he raises his sword. In between doing both of those things, get in some hits with X, as many as possible. What worked for me was to limit my attacks, then just hold B for the inevitable counter-attack. Deplete his health bar, and you move on to the boss battle proper.
Part 4 --
He has two stages. In the first stage, I didn't find much use in blocking. He has a variety of attacks: one where he stabs the ground, which can be avoided by getting away from him. One where he jumps up and a second later comes down at you, which I never managed to avoid with any regularity. He will also do a forward attack, a kick attack, and a spinning attack, all of which are best avoided by dodging backwards as much as possible, rather than to either side. Dodge burst never worked for me here.
After an attack, he seems to be vulnerable for a short while. Get in as many hits as possible, but the moment it looks like he's recovering, dodge backwards again. When he blocks, use Guard Smash (hold Y and release) to stagger him and get in extra hits with X.
Once his health is depleted, be sure you've saved at least one blood rose on your meter, and use the by-now familiar RT+X (when prompted) to finish his first stage.
The second stage, surprisingly, seems a little easier. Get in close for hits, and he'll try to punch you. Dodge-burst with B + move the stick to either side, and get in X's during the burst phase. You can keep hitting him a few times afterwards, but he'll punch again, and you can dodge-burst again, chaining them together. If you mess up, don't worry. He does have an area attack, but you can get back to avoid it.
When he brings his sword across his chest to guard (like in stage 1), hold Y for just a brief time (indicated by controller vibration) and release. This opens him up to more attacks, and you can probably get back into chaining dodge-bursts again after that. This requires the upgrade "Guard Crush" though, which by now, you should have made a point to purchase.
Again, after his health is gone and the prompt appears, use RT+X to finish him off.
This battle is also made simpler with upgraded "Healing" from the Status & Upgrades. Since you're building up your Blood meter by doing melee attacks, you'll be able to get some distance and use LB to heal, thereby conserving Mika tickets. Just remember that there is a couple second delay after letting off LB where you don't have control, so be ready in advance to stop healing and get away before he's right there on you again.
Once you finish him and the cut scenes play, you'll get the achievement when the mission stats screen is shown. Congratulations!