Kingdom Hearts Re: Chain of Memories

Castle Oblivion is set in the midst of large grassy plains and hills. When one reaches the castle, there are rough stalagmites sprouting from the ground. The castle's architecture is very remarkable, with its tower's tops resembling an interesting isosceles triangle, and a noticeable monster with horns on the center of the castle.

Alex, the flurry of Dancing Flames. He wields fire and enhances his weapons, twin chakrams, with his pyrokinesis to unleash powerful rapid attacks.

As the gang continues to reach to top of the Castle, they run into Larxene and Sora remembers his friend's name.

As the gang continues to reach to top of the Castle, they run into a familiar friend, who is acting strange.

As the team reach the top of the Castle, they meet Vexen, the Chilly Academic.

Being fed-up with everything, Sora runs off and leaves Donald and Goofy behind to look for Naminé.

Sora finally finds Namine and has to fight both Riku and Larxene again.

Marluxia, the Graceful Assassin, and Sora's final opponent in Castle Oblivion.

Riku awakens down in the castle, and as he goes up the basement levels of Castle Oblivion, he must take control of the inner darkness inside of him.

As he continues his way to the top, Riku meet another version of him.