The Last Story/Gurak Warship

Take command
During all the confusion, Dagran's injured his eye, leaving you to take charge of the party for a while. With this, you learn a new skill, Command Mode. This allows you to issue commands to other party members when your Skill Gauge is full by pressing. Now, you need to lead the party into the warship. Walk up to the ladder, and press to climb down when prompted. Climb right, up the ladder, and right over the cannons. At the end, you'll climb up automatically. Head down the stairs to the left, and enter through the door. Look right to see a Gurak unaware of your presence. Slash him to save the human prisoner. He's bleeding, so you'll need to get Calista to help him. Open the door to the right to let Calista and Dagran in. Once he's healed, the prisoner will ask you to help the others, including some who were wearing "dandy clobber like you lot" - presumably Mirania and Yurick. Afterwards, you can speak to this prisoner again to have him upgrade your gear. Head up to the door where Dagran is standing.

Peek outside to see a Gurak with his back to you, asking for a good hiding. Serve him his request, then head up the stairs to the right to find another Gurak to be taken care of. Follow the ship deck to a door, enter, and climb down the ladder inside. Below deck, Calista runs ahead, and gets caught by an Ogre. After a few seconds, an attack from a Lazulis ship will kill it. Head up and right. Lure the Gurak Fighter over with an arrow, then silence him before he calls for help (even if he does, it shouldn't be much of a problem; just take the leader out first). Head up, and repeat the process with the next enemy. Make sure you pick up the Lift Key, and use it to open the lift in front of you. There's no lift, so look down and left for the ladder, and climb down to the ship's hold.

Rescue Yurick and Mirania
Open the door, and follow the passage through the hold. At the end, you'll find a guard, holding Yurick captive. A Slash should defeat him. Pick up the Rusty Set of Keys, and free Yurick (use the rose-shaped key). Head through the door opposite the cell. Use the Save Point, and enter the door to the left. Through here, the passageway is flooded. Swim up and free Mirania by shaking around, then return to the Save Point. Mirania gives you a key, which will open the large door to the left. Head in, and you'll get attacked by a group of Spiders. Their fronts are guarded, so you'll need to attack from behind. Use Gathering liberally to give your allies ample opportunities to attack, and also try rolling with to get around to their backs. After a while, Dagran will join the fight. You can team up with him by using Gathering to get the spider to face you, allowing him to attack from behind. The battle shouldn't take too long. After, climb the ladder that the party gather around.

At the top, two Gurak are mercilessly flogging a human prisoner. Lure the guard over with an arrow, then take him and the slave-driver out. Speak to the rescuee to get some Gurak Dust, used to upgrade Gurak-related equipment. Go through the door to the left to find an area with two Gurak Fighters, and a Healer. Lure out the first Fighter with an arrow. When he's defeated, do the same to the next Fighter, and the Healer, one-by-one. After you free the humans, though, more Gurak enemies will appear, this time including Archers. You, however, now have the revenge-seeking humans on your side. Take care of the Archers first, or else they'll play havoc with your mages. After the battle, join your allies in front of the lift. At the top, you'll need to take down an Ogre before assaulting the captain. Lure it over and Slash it. Enter the door at the foot of the staircase. Inside is a prisoner who can upgrade your equipment. Enter the door to the right. Use the Save Point, and head up the large staircase, and through the double doors.

Boss: Muruk
Inside the Captain's room, the Captain summons his pet Muruk for you to play with. The Muruk's weak point is its soft underbelly. Evade its attacks for a while. Soon the Muruk will begin spinning, and firing off spikes that will paralyse anyone they hit. Make sure to diffuse Calista's magic, since this gives protection against the spikes. Alternatively, hide behind a pillar (or what's left of one) until the Muruk becomes dazed, and stops. Run out and attack it to knock it over, then press to climb up, and press  rapidly to attack it. Repeat the process until the Muruk is dead. For added damage, run through one of Yurick's fire magic circles before attacking, since the Muruk is weak to fire. With the Muruk defeated, you now have complete control of the warship.