Complete mission walkthrough:
You will have to start this mission by watching a long cut-scene (#1). As you've probably noticed, the scenery for this mission is going to be very interesting. Your first objective here will be to find one of the hidden items. As a result, you will have to ignore the monsters. Head on to your left. Use the stairs (#2). Destroy the crate and locate the first pendant. Go back to the main deck.
You could try and score a much needed combo sequence right away (#1), however I'd personally wouldn't recommend doing that, because you wouldn't have any enough time to take care of two other subquests. Additionally, Miss Elizabeth isn't a good fighter and it would take her a lot longer to achieve a decent chain. There are three groups of crates on this ship. It would be a good idea to make a stop near the group located on your left (#2).
Each time you will have to do the same thing, so you should read this description carefully. Once you're standing near the crates, press and hold the block key. This should allow you to attract some of the nearby creatures. Now you will have to wait for the boss to begin the attack. Perform a dodge move and wait for the crates to be destroyed (#1). The second group can be found in the central part of the ship. As for the attacks of the boss creature, it will be using mostly lightning strikes (#2). If you see a white spot on the ground, this means you will have to leave this area at once. You will have about 2-3 seconds to do this, however you could also stay a little while longer in order to ensure that the attack will also kill some of the monsters. As a result, you will be completing two side missions at the same time.
The third group of destroyable crates can be found on your right, near the second staircase (#1). Make sure that none of the monsters blocks you from the left, because you wouldn't be able to escape from the attack of the boss creature. Wait for the lightning strike to destroy these crates. If you haven't received new orders, you can consider spending this time on killing additional monsters (#2). You could also wait for a new attack of the boss creature in order to trick them.
Now you will have to deal with your first timed objective. Ignore all nearby monsters. I'm sure that you've destroyed all three crates by now, so you should head on to a glowing area (#1). As a result, you are going to be transported to a deck of the second ship. Before you go any further, destroy the crates and pick up a second pendant (#2).
Now you will have to go to a designated area of the map (#1). You won't have to assist one of the allied units directly, however each time you decide to leave this area, a time meter bar will reappear on your screen. Don't leave this deck just yet. You should be able to find a new group of crates here (#2). Stand next to them and wait for the boss creature to begin its attack. You will also have to watch out for tornados. Make sure that your character won't end up inside one of these traps, because you'd lose a lot of health points.
Now for the hard part. You will have to go left. This means that you will be racing against time. Find a new group of crates, press and hold the block button and wait for the boss to attack you (#1). Once you've destroyed these crates, go back to the fighting area. Make sure that these actions won't take you more than 20 seconds. Wait for the new orders to appear on your screen. You will have to go right (#2).
Some new allied units are fighting the monsters here, however you may ignore them. Head on to the last group of crates (#1). Obviously you will have to wait for the boss creature to attack you. It's probably going to be a tornado, so make sure that you've dodged it. Also, this is going to be your last chance to kill the monsters for the second subquest. Once this is done, head on to the fighting area (#2) and kill a few creatures. You could also try and score a much needed combo.