The Straw Hats and their friends find themselves in groups scattered intermittently throughout a wooded area with clearings placed randomly throughout. Franky and Chopper find themselves facing Baby 5 and Machvise.
Franky: This is where we settle the fight my friends got involved in on Punk Hazard. You and me, princess.
Baby 5: I've been looking forward to this!
Chopper: That means it's you and me, swirls!
Machvise: Baby 5, I need you to do that thing for me that you did before.
Baby 5: I'm needed! Ok!
She transforms into a cannon. Machvise loads himself, and she shoots him at Chopper. Chopper blocks with Arm Point but still crashes through some trees.
Franky: Strong Right!
Baby 5: You'll have to do better than that! Armory Girl!
Dozens of various kinds of guns come out of her arms, all pointed at Franky.
Franky: Oh, please.
Franky opens up his entire upper body, showing a multitude of guns, rockets, and bombs. Both now stare at each other in a Mexican standoff. Elsewhere, Law, Sanji, and Kin'emon are dealing with Dellinger, Diamante, and Lao G.
Lao G: Trafalgar, let's see if the student has surpassed the master. I hope you'll honor our agreement and not use your Devil Fruit powers, as I will not use mine.
Law (grinning while drawing Kikoku): I wouldn't have it any other way, Lao-sensei.
Law charges at Lao G. The old man blocks his sword with his middle and index fingers. The two begin a classic swordfight of blades clashing with...fingers.
Sanji (pointing at Diamante): Alright, stretch, me and you. I hope the rumors are true. They say your kicks are as tough as diamante.
Diamante: Oh, they don't really say that.
Sanji: It's what I've heard.
Diamante: You are quite the flatterer, there's no way that's true.
Sanji: Fine, they aren-
Diamante: But I hear those rumors are true as well.
Sanji: Let's see how you measure up to my new Kuroashi Yorimokuraku Style!
Diamante: Yes, let's!
Kin'emon: That leaves you and me. Know this, "Horned Sword" Dellinger, my Foxfire style will turn you into hamburger meat. My blades will eat well tonight and I will get my son back from you heartless beasts!
Dellinger: I knew you were a fool, but I didn't know you were a pansy too.
Kin'emon: Excuse me?
Dellinger: Suicide is the coward's way out.
Calves and swords collide as the fighters clash. Meanwhile, Nami, Robin, and Brook have their hands full with Trébol and his army.
Trébol: So, either of you have dinner plans later?
Robin (using her powers to push him back to a socially acceptable distance): You're not our type.
Nami: There is no way I'd think of doing anything with an actual slime ball like you ever!
Trébol: Come on, I'm nice once you get to know me...
Brook (stepping in between him and the others before he gets too close): They said no. If they won't show me their panties, there's definitely no chance they'd show them to you.
Nami: That has nothing to do with it!
Brook: Your fight is with me. If you ladies would take care of the rest.
Nami and Robin: Got it!
They begin their fights. Nami and Robin aren't having much difficulty with the peons, and Brook's freezing slashes seem to be having some effect on Trébol. Lastly, Luffy, Zoro, and Usopp are running when they come up against the spade seat holder, Pala, the top hat gunman, Zoma, and Jora.
Zoro: Alright metal man, you're supposed to be this great blade master. So why don't we put your title on the line?
Pala: SOUNDS GOOD!
Usopp: You, gungimp. Let's see whose shots are better!
Zoma doesn't say a word, just points his pistols at Usopp as he gets ready to fire his Kabuto.
Jora (making her art cloud thing): Well, I guess that leaves me with the cute one. Tell me, hon, what inspires you?
Luffy is a bit impatient, so, without breaking stride, he sweeps Jora out of the way, breaking her art cloud, and sending her unceremoniously face first into a nearby tree as he runs past her.
Luffy: Sorry granny, can't talk, I gotta find your boss!
From out of nowhere, Doflamingo drops down from the sky.
Doflamingo: I'm right here, Straw Hat. You should tell me your funeral arrangements now. It'll be the least I can do after my friends and I wipe you out.
Luffy: No way! Gomu Gomu no Gigant Pistol!
Luffy engages Doflamingo, who nonchalantly dodges and deflects Luffy's attacks, countering with hits that could be a lot stronger.
Nami: Something isn't right about this!
Robin: I know what you mean. For an army, they move far too much in sync. It's like sloppiness perfected. They're coordinated but I still can't read them that easily.
Kin'emon: Doctor swordsman, this battle is strange. There is syncopation to their movements, yet the battles are separate.
Law: I know. This is nothing like Lao G's old style. It's limp, almost nonchalant, yet forceful.
Sanji: I can sympathize. This guy's fighting style is the smoothest I've ever seen, yet there's no method to his flow.
Brook: Something is odd about our blobular friend and his minions. I'm only feeling half the number of souls I should be. I can only sense some, yet there are dozens if not hundreds of them. If I can align my biorhythms...there! Soul Augmentation: Heavenly View!
Brook separates himself from his body. Aligning his biorhythm with Trébol's, he puts his body in a sort of autopilot so it avoids his attacks. His soul is now enormous, ethereally taking the form of his body, including his violin. He looks down on the battlefield as if he were God and the field his chess board.
Brook: I knew something was up. Nice to formally and divinely meet you, Heavenly Yaksha.
Doflamingo: The pleasure is all mine, Soul King.
Before him, on the other side of the battle area, is Donquixote Doflamingo. In a sort of sitting position, he is coolly plucking a mandolin at his side. His hands and eyes are glowing and the glow from his hands seems to trickle down onto the battlefield through his mandolin.
Brook: I never imagined you'd be capable of something like this. I thought I was the only one with a soul this powerful.
Doflamingo: As a kid I was often told I was getting too big for my head, so I found a way around that, so to speak.
Brook: Mind and soul are connected, and your ego controls your mind, so that is understandable.
Doflamingo: Fufufufu, look at us. The two kings of the Underworlds enjoying a heavenly view of a battle. I do so enjoy life's little ironies.
Brook: Yohohoho, indeed. I understand now why our battles seem so strange. Half of your people down there are under your direct control. The other half are under your hypnosis, acting upon some kind of unconscious commands. That mandolin is the medium through which your power up here is projected.
Doflamingo: My my, you do catch on quick.
Brook: Well, it's time to end this.
Doflamingo: You cannot break my control, skeleton, don't even try.
Brook: Who said anything about your control?
Brook takes out his violin, and using Soul Solid as the bow, plays a quick melody as ethereal light snakes its way down to each of his friends.
Brook (thinking): My friends, please forgive this intrusion. Know that what I do I do only because I have your best interests at heart. I never thought the day would come that I would have to put my own crewmates under my hypnotic power. Forgive me.
He begins to play. A single, low note is heard from his violin in a repeating rhythm: half, rest 2, quarter quarter half, rest 4, half.... After a playing this a few times, he stops and looks at Doflamingo, who is smiling with the kind of excitement one only gets from finding a truly worthy opponent.
Doflamingo: And now the real battle can begin.
The two heavenly bodies each begin to passionately play their respective instruments. The music heard from them is unlike anything to ever grace mortal ears. The dueling sounds create a symphony but at the same time clash all the while. Their passionate crescendos, decresendos, fortissimos, and fortississimos translate down onto the battlefield. Doflamingo never stopped his original melody.
Nami: Black Cloud Tempo: Lightning Brew!
Robin: Mil Fleurs: Rain!
One thousand hands sprout from Nami's cloud. As the cloud breaks up, charges gather and the pieces of cloud fall to the ground, carrying the electric fists with them as if Thor himself were raining his might down upon the army. Luffy is now employing a fighting style far different from his own, this one reminiscent of capoeira and judo and is actually landing hits on Doflamingo. Diamante and Sanji have taken to the air and each hit releases a crashing sound.
Zoro: Asura Incarnate, Akatsuki no Mai!
Zoro's clash with Pala reverberates with astounding acoustics, creating sonorous contrast to that of Sanji and Diamante. Kin'emon and Dellinger are exchanging blows with a fiery passion that rings out like a horn section.
In Mariejois, one of the gorosei is keeping time with seemingly non-existent music.
Sevelt: Hershel, what is Mancha doing?
Hershel: I couldn't tell you. He must hear music from somewhere.
Then the two musicians for some reason exchange melodies, but not dynamics. Suddenly Luffy finds himself fighting Trébol and Brook is fighting Doflamingo now on two planes, none of their strides broken by the change in opponent. Brook unexpectedly picks up the tempo and after several fortissimo staccatos that take Doflamingo by surprise, suddenly there is just one battle left unresolved on the ground, their own, their music suddenly taking a more somber tone without slowing down as the victors stand still in their trances.
Brook: And now we go into the final movement. May I just say, that regardless of how this turns out, it has been an honor playing with you.
Doflamingo (grinning as always): Likewise.
On the ground
Doflamingo: Your sword attacks are doing nothing but giving me minor damage and making me chilly. Is this all you have?
Brook: No. Not by a long shot.
He thrusts his hand forward and a cold wave stops Doflamingo in his tracks.
Brook: Not only can I call forth the coldness from the underworld, I can also call forth its darkness. Behold, Dark Symphony!
Dark energy (nothing like Teach's, stfu) accumulates around Brook's sword.
In the sky.
Brook: And now this ends! Lullaby of Shadows!
Brook pulls his sword across his violin one last time, releasing a dark wave as he does. The same motion happens simultaneously on the ground, sans violin. The wave hits Doflamingo, sending him flying back, hitting the ground. Ethereal Brook holds his bow up to his face before swiftly bringing it down to his right-hand side before both souls, exhausted from their fight, fade back to their bodies. The return shock sends Doflamingo into unconsciousness while Brook merely collapses from fatigue as his friends rush over to help him.