Symphony of Sorcery
Just like Timeless River and Country of the Musketeers, this is a world set back in time from when King Mickey was in pursuit of becoming a Keyblade Master. This is where he trained as an apprentice under Yen Sid and found out the hard way not to sleep on the job and let the walking brooms do all of his chores. The world itself is quite a wonder since it seems to shift between realities. Beware, Chernabog resides here as well.