Alright, I'm gonna do this one without planning it through whatsoever, let's see how this goes.
Title: To the Top
Cover Story: Hey, let's just go and chase those fleeing fish over there!
<Robin continues her battle with Gladius, while Bartolomeo maintains his barrier staircase>
Robin: Shark-man, when Luffy and the others get to Level 4, put the stairs away and come help me!
Bartolomeo: Sure, sure...hmmm, come to think of it, I can't see where the stairs end! I'm not sure whether or not Luffy-senpai is on it, so I better keep it up for good measure!
Gladius: So your captain thinks I'm only good enough to deal with you trash? He's just gone and killed himself now. The Young Master could filet him within seconds...though I still don't expect your captain to get through the rest of the Guard!
Robin: Spare your words! They mean nothing if you cannot act on them!
Gladius: Oh? Well then, watch me...
<Gladius throws more Rupture Balls at Robin. They appear to be successful, and Robin is thrown to the ground, injured>
Gladius: Let this speak for me...as well as for your weak self!
Robin: If that speaks for you, I think it's saying...you're rather stupid.
<The Robin in front of Gladius disappears, and he looks back to regretfully see her standing behind him. The other Robin had been a clone>
Robin: Tut tut...you called us, including my captain, trash, but look now. Where are we, and where are you? No matter. Trash can always return...back to nature! Cien Fleur: Ivy Stranglehold!
<100 Robin arms sprout from the ground and envelop Gladius. Though he is caught and unable to move, Gladius chuckles, and puts his finger on one of the limbs. It then begins to swell up...>
<Meanwhile, Cavendish finishes off the last nutcracker, and after making sure Farul is resting, races for the stairs>
Cavendish: Bye, shark-face! Don't let that creep touch my horse! And don't YOU touch my horse either!
Bartolomeo: Right when I was gonna put this away...
Cavendish: I'm still coming for you, Doflamingo! You're all mine! Luffy and the other two went first, so I bet one of Doflamingo's guards is dealing with them! Giving me the chance to go and take his head! Even the "Worst Generation" will be in awe!
<Meanwhile, Usopp's squad has to deal with the mob coming for their heads, climbing on the web>
Usopp: I'm out of ammunition! I don't know how to deal with this!
Kanjuro: Never fear, God-Usopp! For I have made a solution! <points to recently created solution>
Usopp: GAAAAAAAHHHHHHHH! YOU CAN'T BE SERIOUS!
Kanjuro: Yep! For all the flies on the web...are food for the spider!
<Kanjuro's solution, a poorly drawn spider, is sent onto the web, sending the mob into panic>
Mob Member 1: GAAH! WHAT IS THAT THING!
Mob Member 2: I'd call it a spider, but its body is so weirdly shaped, and what-IT ONLY HAS SEVEN LEGS!!! WHAT KIND OF THING IS TH-gaaaaahhhhhaaaa! <Kanjuro's spider attacks the mob using its fangs and seven legs>
Usopp: I have to say, Kanjuro, you actually had a good idea this time!
Viola: Now that that's out of the way, we need to get to the palace quickly to find Princess Mansherry!
Kanjuro: Right ahead of you! <summons a poorly drawn war eagle, which spans almost the whole plateau and has many decorations to draw attention to it>
Everyone else, in unison: NO!
<On the other side of the plateau, however, a citizen looks at the four in glee. Their quarry has been spotted. Suddenly, a cry for help sounds from across the plateau, drawing the attention of Usopp's group>
<Elsewhere, the battle between the manliest men in the world continues>
Senor Pink: MANLINESS EXPLOSION!
<Pink rolls around with his arms up over Franky, exposing him to an intoxicating gas>
Franky: Gah! That did NOT feel super! Rrrr...I'm running low on Cola too! And this was my emergency supply! <notices a container of an unknown liquid> Well, better than nothing! <drinks the entire container, causing everyone to become shocked>
Kyuin: You fool! That was a container of a chemical we use for SMILE! Consumption of it causes parts of your brain to shut down temporarily!
Franky: Oh, that was a nice drink...now I feel...I feel...EXTRA SUPERRRRRRRRRR!
Kyuin: His manliness is only accentuated now! <she and the female entourage swoon>
Franky: Oh yeah! CHEST HAIR BULLETS!
<Rapid-fire bullets pop out of Franky's chest, and Senor Pink struggles to dodge them. Franky continues in a drunken rage, ripping parts of the wall out>
Senor Pink: What is this man? I can't...keep up with this display of manliness!
<Elsewhere, Luffy and Law prepare to head up to the final level of the palace>
Kyros: I'll join you once I'm through with this! <Kyros slashes at Diamante, and the latter counters with a waving sword>
Kyros: I see your sword trembles, Diamante. Now I'M GONNA MAKE YOU QUAKE!
Diamante: Let's see you try, Kyros the undefeated champion! I've never been defeated either, so this will go down in the history books!
<Meanwhile, Luffy and Law keep running>
Trebol: Those two upstarts are getting closer and closer to us! I sure as hell won't let them! Sticky Bombs!
Law: If those hit us, we won't be going anywhere! Fortunately, I have my powers back!
<One moment later, Law transports the bombs behind him, and they explode on empty ground. Trebol fumes, and reaches for his next weapon>
Law: Getting close-WHAT THE F??????!!!!!!!!!
<To his and Luffy's horror, somehow Trebol has managed to grab a full-size ship and chuck it at them>
Law: Don't you worry, Luffy, I've got this!
<Law activates his powers once again and slashes the ship into tiny pieces before it even gets close to him>
Trebol: No!!! That was my best ship!
Doflamingo: It looks like that Law is causing trouble. This wouldn't be such a problem if it weren't for...Corazon!
Luffy: We've made it! Hang on! <stretches his arms until they reach the top of the palace> GOMU GOMU NO...ROCKET!!!
<Luffy, with Law hanging on to him, rockets up to meet his destiny>
Law: This race to come here...it feels like the day I first met Corazon!
<Luffy and Law fly and reach the top of the palace, making eye contact with Doflamingo and Trebol. Law's and Doflamingo's minds, however, are wrapped up in things of the past. Time flashes back again to 13 years ago, with a suicidal Law wanting to join the crew>
Law: If you don't let me join your crew and let me live my life to the fullest before my illness takes me, I'll blow you all to smithereens!
<Suddenly, a person quite similiar to Doflamingo, but with brunette hair and sharper facial features, comes out of the shadows>
Corazon: Don't worry, Doflamingo. I'll take care of this one.