Black Bowser's Castle

Black Bowser's Castle is the final area in Paper Mario: Color Splash. It is on a floating island with an appearance similar to that of Bowser's Sky Castle, but with pipes leading into the rock. A rainbow road, leading up from the Prism Fountain in Port Prisma all the way to here, is unlocked once Mario has retrieved all six Big Paint Stars.

Layout
The castle's entry hall consist of a hallway where Princess Peach's portrait is initially seen, just out of reach. When Mario attempts to lower it, however, a trapdoor opens leading to a confrontation with Roy Koopa. A door in the pit leads to a factory where all the paint stolen from Prism Island is brought to mix into Black Paint. The Black Paint is then used to color weapons such as Banzai Bills and Bob-ombs, which Black Bowser intends to use to paint the world black. Mario manages to destroy the tank holding the Black Paint which floods the factory. The factory also has a warp pipe leading back to the entry hall.

Behind the wall where Peach's portrait was is a hallway leading to Bowser's throne room, with the princess now hanging above the throne. After Black Bowser is defeated, the castle begins to collapse, due to the Black Paint. Mario, Luigi, and Peach escape while Huey stays behind and, to ensure the Black Paint does not fall into the ocean, squeezes the castle, removing the black paint and transforming it into a card.

In battle, the Black Bowser's Castle card summons the castle and crashes it into the opponents. It is also powerful enough to instantly defeat Black Bowser in battle.

Enemies

 * Bob-omb
 * Hammer Bro
 * Ice Bro
 * Slurp Guy
 * Paint Guy

Bosses

 * Roy Koopa
 * Black Bowser