Atop Flopside Tower is a solitary ominous door. Nolrem is also there, saying it's the final door. It's the eight Pure Hearts vs. the Dark Prognosticus and Castle Bleck awaits. Merlon appears, saying that on the last page of the Light Prognosticus it says that only those who have not abandoned hope can turn back the prophecy of doom. They walk forward into the future, no matter how dark and uncertain. Nolrem says they fought all this way because they believed the future could be bright. He can't go through the door with them, but sends them with all the hope in his heart. Peach thanks both of them and Luigi says to leave it to them. Bowser asks if they're going to group-hug and has had enough of the pep talks. He's doing this for himself.
Merlon says he doesn't know what's going on in Tippi's mind, but suggests that she stay behind if this is too hard for her. Tippi says she's going, having decided that she must do this. Merlon wonders what would happen if her memory returns and says she's grown so strong and changed so much. He says she must return safely to him. Tippi says she will go and defeat Count Bleck and save all worlds from destruction. The ground shakes. Nolrem tells them to hurry as all worlds may not have much time. In that black span of nothing, they will find Castle Bleck. They may face battles harder than any they've endured thus far. Once they feel ready, they should go forward. Merlon tells them all, Tippi included, to be strong. When you're ready, go through the door.
After finding every Pure Heart, the band of heroes set off for Castle Bleck. The stakes were high as the ominous void grew larger and the end drew near. Could Mario and friends stave off the inevitable and overturn the prophecy? What strange twist of fate awaited Tippi and Count Bleck? These thoughts plagued the minds of our heroes as the curtain rose on the final act...
The heroes find themselves at the Castle Bleck Entry. Castle Bleck looms, a black castle with a white outline and a cracked door. Flip into 3D to go through the door. The inside of Castle Bleck, as we've already seen, is black. This makes it sometimes difficult to distinguish enemies such as Magiblots, which are in the first area. There are also Koopatrols in the first room. To the right is a door. Through it, you'll find stairs with Goombas, Boomerang Bros. The door in the middle takes you outside where there are Paratroopas and Koopas. Go back inside and through the door at the top of the stairs and you'll find Red Is and Mr. Is. Run around them in 3D to defeat them. To the far right is a locked door. Walk a short distance to the left and Super Jump up to a door that leads to the outside.
Super Jump to the left to find two chests with a Long-Last Shake and a Stopwatch. Super Jump to the right, then float to the right to a pipe. Go through the pipe and you'll find Magiblots and Soopa Strikers in a narrow hallway. They're even in 3D. On the other side is a chest with a Castle Bleck Key. Go back through the pipe and go through the door, then unlock the door to the right. There are Dry Bones here, as well as Magikoopas, Gawbuses, Tech Cursyas, and Heavy Cursyas.
Go through the door and you'll find Magiblots and Fire Bros on the stairs. At the top are a set of five white torches. Take note of which ones are lit. Go up another set of stairs, which has Koopatrols at the top. The item block contains an Ultra Shroom. There's a Save Block nearby. Go through the door and you'll find large white torches. Have Bowser light the same ones as in the previous room and a large set of stairs is drawn in. Flip into 3D to go through the door.
Someone says "Harble-deh!" It's O'Chunks, who never thought they would make it here. He says the heroes shouldn't have been a pain. He has to hit them with the full force of his chunks. Bowser calls that big talk for a chump that gets stomped again and again. He says chunky boy is going down. O'Chunks tells him to prove it in a wrestling match of the ages. Bowser says he'll take on O'Chunks alone. Peach asks if he's sure and he says he's had egg-salad sandwhiches chunkier than him. He tells her to step back and watch how a totally awesome tyrant gets business done. The bros and Peach leave. O'Chunks says he'll hurtle into him with the force of a massive, hairy comet. He grows in size and Bowser is shocked. O'Chunks says Bowser wasn't expecting that. It's time to rumble.
O'Chunks has 100 HP and 4 attack. Because I went through the Pit of 100 Trials once in Flipside and twice in Flopside, I am now level 27, making Bowser incredibly powerful. Two blasts of fire breath doing 60 damage each beat him easily. When you win, O'Chunks shrinks down to normal size, wondering how Bowser could be chunkier than him as he's nothing but a turtle. He doesn't know how he can go on living with the shame of it all. He asks Bowser to let him keep his dignity as his game ends by finishing him off quickly. Bowser says there's no shame in being smacked down by a huge, studly boss. The ground shakes and the ceiling starts lowering. O'Chunks holds it up. Bowser asks why he saved them. O'Chunks tells them to get out of there. Bowser asks why he's doing that for them and O'Chunks says they beat him so they earned the right to pass. Bowser says he has more chunks in his head than he thought and holds up the ceiling as well. O'Chunks asks what he's doing. Bowser tells the bros to get the princess into the next room immediately. Luigi tries to protest, but Bowser barks at them to go. Peach agrees after a long pause and they leave. Bowser tells O'Chunks to go, too. He can hold up the ceiling all day. O'Chunks says he stole his line and that Bowser's hands are quivering. There's no need for Bowser to be a tough guy, so he should go. Bowser says he is a tough guy and tells O'Chunks to get out. Both of them tell each other to go and the ground shakes even more.
On the other side of the door, the bros and Peach hear a thud. Luigi calls to Bowser and checks the door, saying it won't budge. Peach says they have to keep going as there isn't much time. She's not worried about Bowser; he's not easy to get rid of. Luigi agrees, saying he's survived worse. Peach says they must move on to find Count Bleck. Bowser is no longer in the party, lost to them from a battle of machismo. The star is just to the right.