Neo Bowser Castle (Mario & Luigi: Dream Team)

Neo Bowser Castle is the final area that appears in Mario & Luigi: Dream Team. On Pi'illo Island, it doesn't appear until the middle of the game, where it appears floating high above the island, until it is grounded and lands in the east, north of Somnom Woods and east of Mount Pajamaja. It can be reached by traveling north in the area between Mushrise Park and Somnom Woods.

History
At the summit of Mount Pajamaja, with the Dream Stone charged, Antasma wishes for a castle for him and Bowser, one that is impenetrable and also one that is feared. A large castle, a mix between Bowser's and Antasma's designs, comes out of the Dream Stone and floats into the sky. Antasma then tries out the castle and destroys several small islands around Pi'illo Island with large lasers. Then a large impenetrable shield surrounds the castle. Bowser dubs this castle Neo Bowser Castle. Inaccessible for most of the game, Mario and Luigi gather the parts of the Ultibed to reach the Zeekeeper in the dream world, as he is the one who can break the shield surrounding Neo Bowser Castle and send it to the ground so the brothers can defeat Antasma and Bowser.

When Mario and Luigi storm the castle, most of the important areas are blocked with sturdy gates that must be lowered by pressing several switches that power the gate using all the navigational techniques they've learned through the game. Kamek will also hinder progress several times by casting spells on the doorways, warping the brothers in different sections than they intended, before going through dream portals created by Antasma. Scattered throughout a floor of the castle are white blocks with Kamek's hat on them that are used to reveal exactly where a spell warps the Bros. to and from on the map. By lowering the gates blocking floating Koopa Clown Cars that Luigi can use to sleep on, the Bros. can get to Kamek through the puzzle-laden dream worlds, where they can defeat him to lift the spells placed on the doors so they can move forward. As they travel up the castle, Giant Bob-Ombs will also come into play and the brothers must use air vents to navigate them into pressing the gates' switches if their abilities alone are not enough.

Deeper in the castle, after defeating Kamek a third time so that he no longer casts spells on the doorways, the brothers are stopped by several intense dark flames being shot out of portals from three Dream Worlds, which they must make their way to and destroy the pipes spewing them.

Upon succeeding in doing so, Mario and Luigi enter the doorway at the end to find Bowser sleeping on Antasma as a pillow with a barrier protecting him. Dreambert states that the strange purple vines they've seen everywhere throughout the castle are what powers the building, and that they originate from Antasma. Luigi suggests they enter Bowser's Dream World, Dreambert realizing they could try what they did with Big Massif with Bowser. Dreambert connects himself to the vines as pillow form, and Luigi sleeps on him, Mario entering the Dream World where he and Dreamy Luigi confront and take down a powered-up Bowser. By defeating Bowser in his Dream World, the vines that supplied the power to the castle turn gray.

Mario and Luigi leave the Dream World and after pursuing the evil duo, discover that Bowser was planning to double-cross Antasma all along. Antasma reveals he had made a wish on the Dream Stone for the ability to create Dream Portals at some point, and flees from Bowser through one. Bowser, meanwhile, flees himself with a Paratroopa holding Princess Peach. Dreambert decides to fight Antasma just as he did centuries ago, and loses. Mario decides to avenge him and jumps into the Dream Portal himself. Dreamy Luigi and a barely conscious Dreambert join in the fight to assist him. After Mario defeats Antasma for good, they leave the Dream World, knowing they still have Bowser to take care of.

The Bros. then work their way up a long spiral passageway, and narrowly avoiding Private Goomp, Sergeant Guy, and Corporal Paraplonk's Bob-omb attacks, Mario, Luigi, Starlow, and Dreambert make it to the castle balcony, where Bowser and Peach await. Bowser boasts about the power he now has, with the Dream Stone and Peach in hand. Suddenly, Peach and Starlow activate their wish power from the previous game and, at the request of Dreambert, destroy the Dream Stone. Bowser is initially shocked about this, but then screams in rage, "NOT YET!" as he inhales the Dream Stone's pieces and becomes a form known only as Dreamy Bowser. Mario and Luigi engage battle with him, and upon winning, knock him flying into the sky. Suddenly, without the Dream Stone to maintain it, the castle begins to crumble, but the Zeekeeper gives Mario and friends a lift back to Pi'illo Castle just in time.

Enemies

 * Fire Bro
 * Flaming Antasmaton
 * Inky Piranha Plant (background enemy)
 * Chain Chomp
 * Walker Guys
 * Shy Guy Airtub R
 * Shy Guy R
 * Antasma (boss)
 * Dreamy Bowser (final boss)