Pokemon Colosseum. Loosely based on Tower Colosseum from the same game, it can change into 1 of 5 different forms roughly every 50 to 60 seconds.
Ghost Mode- Resembling an ominous graveyard. The black mist makes it harder to see the surrounding arena. Ghastly, Dusknoir, Chandelure, Drifloon, and Banette can be seen in the background.
Fire Mode- A volcanic appearance. Occasionally the volcano in the background will erupt and cause massive damage. Camerupt, Torkoal, Slugma, Magmar, and Darmanitan can be seen in the background.
Water Mode- A water park like appearance. The terrain is more slippery then normal and pumps may occasional push the players around with water. Floatzel, Jellicent, Psyduck, Marill, and Milotic can be seen in the background.
Fighting Mode- A fighting ring appearance. Its a basic stage at first, but the power of all characters is temporarily doubled. Conkeldurr, Hitmonlee, Riolu, Combusken, and Hariyama can be seen in the background.
Grass Mode- A thick jungle appearence. The terrain is very inconsistent with two levels (floor and canopy) to fight on. Bellossom, Serperior, Canivine, Shroomish, and Exeggcute can be seen in the background