When Riku arrives back from Monstro to Castle Oblivion, he meets a member of Organization XIII: Vexen. After a conversation, Riku challenges Vexen to a battle. It's time for the first boss fight against a member of the Organization. Vexen's attacks are largely ice-based and can do a considerable amount of damage. Attacking him from behind and when he's reloading his deck is the best method. There really isn't much to it other than that. If you happen to tap into Dark Mode, use Dark Firaga and Dark Aura. These moves will come quite handy in this battle. Vexen's attacks include:
- Vexen simply casts Blizzard. Though Riku can't cast this, you should know what this is after completing Sora's Story.
- Vexen uses his shield to slash away continuously at Riku. Jump behind Vexen to stop his attack and bring on one of your own.
- Vexen sends ice Riku's way and freezes him. Not only are you paralyzed, but you gradually lose health until the attack is broken.
- Vexen summons a large blizzard Riku's way. Either dodge or card break if you see him preparing this move.
- Icy spikes shoot up from the ground and follow you wherever you go. It's best not to stand still and run around while this attack is in motion.
Once you've defeated Vexen, you'll learn that the battle was just a trap so Vexen could get date to create a Riku Replica, as seen in Sora's Story. Vexen escapes and now it's off to Never Land.
From where you start, clear the room of Heartless and strike the door. Synthesize using a card with a value of 1 or more. In Room 2, use a card with a blue border and the Key of Beginnings. Here you'll face Captain Hook. If you have the chance to get into Dark Mode, use Dark Aura. Hook only has one health bar, so this should finish him off quite quickly. If you can't, this boss battle isn't any harder than the ones you've faced earlier. Keep chaining combos and card breaking. Hook will be finished eventually. Hook's attacks, although non-fatal, can prove to be quite a nuisance. These include:
- Hook slashes his sword around. This can be annoying if he manages to put it into combos, but a simple card break should do for this attack.
- Hook throws what looks like wrapped gifts at Riku. They explode upon impact in what seems to be a trap, albeit an obvious and silly one. These should be easy to dodge considering they aren't too large. They can get annoying when he throws one after the other though.
When you're finished with Hook, go right to the next room and then right to the room after that. Clear the room of Heartless, strike the north door and synthesize using a card with a value of 3 or more. In Room 5, clear the room of Heartless once again and go through the door to reach Castle Oblivion.