Due to the creation of the game, Castle Oblivion may have two to three areas only. This includes the Entrance, Main Hall and a certain room, but it is not confirmed yet.
↑WingBlade says..."The Wind Sentiment will appear here as a character not an optional boss. I've changed the Wind Sentiment's role because Castle Oblivion is where Sune will restore some of his memories, making the Wind Sentiment a test."
↑WingBlade says..."And I may also include a certain room to make thing more complicated."