Supersmash bros brawl where is tabuu

In The Great Maze, go to either The Battlefeild Fortress or The Swamp. When you see a purple arrow pointing to a door, go through it. If you don't see any trophies there, go through the gate (how you would usually go through regular doors). After a cutscene with Tabbu and Sonic, select 6 characters (Sonic will now be available to play in the Subspace Emmisary) to battle Tabbu.