Okay, I know that a lot of people read the topic title and either did one of two things..
a) rolled their eyes, what can Buggy do??
b) immediately said "Luffy"
.. but here me out.. I'm sitting at work and have absolutely nothing in the world to do except fiddle around on my laptop. During the non-stop thrilling excitement known as security work (sitting on my ass in a small office for eight straight hours), for some reason One Piece popped into my head and I was thinking about the villains (or major players) we've met so far and what role they may play later on. Of course, Blackbeard was the first to come to mind because after watching episode 325, I was reminded of how freakishly strong he has become and how much potential his fruit has.. but this isn't about him… because after a minute of thinking about Blackbeard, I thought of one of Luffy's other two pursuers. The other two happen to be Smoker and Buggy. Now, as much as I love Smoker (he is one of my favourite characters after all!) I don't think he is going to do anything frighteningly immense or become one of the strongest characters in the entire series.. this leaves the pursuer I immediately thought of though, Buggy.
Many people love Buggy, he is one of the most beloved villains in the series. Oda himself also said he is quite fond of Buggy at one point, did he not? Why do we love him? Well, I'm sure many people love his character design, his borderline insane personality, or his crew.. but then there are those, like me, who think Buggy's most interesting feature is his Devil Fruit, which this topic is going to revolve around. Buggy, his Devil Fruit, and its potential.
I look back on Buggy, and at the start of the series he was already looking ridiculously strong. He had a cannon which could demolish an entire town, which had been deserted due to his arrival. He was the second Devil Fruit user introduced (after our beloved Luffy), and he showed that being able to split apart in a cartoony fashion helped him immensely in fights. When I look at the Buggy versus Zoro fight and think of Zoro's loss to him, I like to think of it saying one simple thing.
Buggy > Zoro
Yes, I know Buggy played a dirty trick to get the win, but this was an early arc battle and normally when someone loses to another character - in almost any fashion - it is saying that they are inferior in some way or another. No doubt post Water Seven Zoro would slaughter the Buggy we saw at the start of the series. He has grown so much, but what about Buggy? Is he just taking it easy on his ship? Heck no! This is a manga, and as a rule, Buggy must grow stronger for no apparent reason even though we don't see him. Every major player who remains part of the story, and has decent fighting abilities when first seen, AND tangles with the main character, usually gets stronger over time. It's one of many unwritten shonen manga rules, ya know?
So.. what could Buggy do to improve? What can he do that we haven't seen him do before? What else can he possibly do with his fruit besides split into clumsy blocks and float around? Well.. there is one thing that members here have hinted at before which I think is a very real possibility of the direction Oda may take Buggy's powers. What is it?
Splitting apart at the sub-atomic level.
While it seems like a pretty substantial power-up which some people may shrug off and dismiss entirely - look how much of a power-up Luffy's gears were. I think this could be Buggy's equivalent and it would open up a world of possibilities in terms of what his fruit can do for him. I'm going to go over some of the things I think Buggy could do with the ability to split himself into such small pieces.
Invisibility
While it would not be true invisibility, Buggy would be able to split into billions of small pieces and spread himself all around the place. If he covered enough ground, I cannot think of any attack which would harm him easily. It would also serve as an excellent way to piss off his opponent. Can you imagine Luffy doing.. lord, I don't know.. Jet Storm perhaps, only to hear Buggy laughing?
Teleportation
Again, not true teleportation.. but it would give off the illusion of Buggy doing so. If he could learn how to move fast (soru fast), then Buggy could easily do a "bara bara teleport," allowing him to break apart and reappear behind his opponent in less than a second.. or anywhere else, if he'd feel like it. In fact, I think that this would even be superior to soru, because he would be broken up and again, would be hard to hurt. He could also "teleport" into small spaces or go inside things and reform (such as a sealed bag or sack).
Friction & Heating
Say goodnight, Aokiji. If Buggy mastered the ability to split at the sub-atomic level and then added a bit of Luffy-esque creativity, Buggy could shake/vibrate/move about at the sub-atomic level in small patterns to generate heat and friction. If by chance Aokiji fought Buggy and captured his sub-atomic particles in an attack, and provided that Buggy could withstand it somehow, he could vibrate furiously and melt the ice.
"Mirages"
I would imagine that Buggy would be able to put his microscopic parts back together in any way, shape, or form. By doing so, I think he'd be able reform into false images.. like when you see a mirage in the desert. I'm not thinking like Mr. 2 here with him turning into people, no. I'm thinking of Buggy turning into inanimate objects. An example would be a sign that says "exit this way" or if you'd care for something deadly.. he could break his hand up and let it reform in the shape of a fruit. When eaten, he could reform his fist and clench their throat from the inside.. many possibilities with this idea.
MECHA BUGGY!!!!
Not.. exactly mecha… but if Mr. 3 could create such a complex mech-like body armor out of freaking WAX, then what is stopping Buggy from taking apart certain parts of his body and reforming them as something new? He could reform his hand to be a densely packed blade or axe.. he could make gears and pulleys or simulate an electronic device. The possibilities of this one are endless. The only problem is that Buggy would not be able to go too crazy with this, because unlike Mr. 3's wax, Buggy would only have so many parts to work with, similar to Gaara's sand - he'd only have a set amount to build with.
Implosion
This isn't something I'd expect Oda to do, but Buggy certainly could do it. He would definitely be able to break apart and fly a mass of pieces into his opponent's body. He could then reform whatever he sent inside and create a freakishly strong push on them from the inside. How long could they last before blowing, eh?
I may be overstepping a fine line here, but I think that by learning how to break himself into such small pieces, Buggy would be able to successfully combat almost any character in the series and have an incredible advantage. The only thing I can't think of his how he'd be able to defeat certain logias such as Ace.
If Buggy learned to separate at the sub-atomic level, he would take his battles to a whole new level. I'm convinced he'd be able to kill several Straw Hats. Zoro, Sanji, Usopp, Robin, Chopper, Franky.. what would they be able to do to something they cannot see and is spread out all over the place? Notice how I only left one person besides Luffy? Yes. Nami.. I think that is she created a wild downpour, Buggy would have almost no mobility. The weight of a rain drop is certainly more than a microscopic piece of a clown pirate. A wild rain shower would be costly conditions for Buggy to fight under.
So.. I suppose I have only named three people who would stand any sort of chance against Sub-atomic Buggy.. but lets throw in all the logias except Blackbeard, because we're not sure exactly how far his fruit could go just yet. He seems far more vulnerable than most logias though.
Anyway… who do I think could defeat Buggy in this form?
Ace (fire would burn Buggy's microscopic butt)
Enel (lightning is not matter, there is nothing Buggy could do)
Who would probably battle Buggy to a stand-still, or win/lose by a slight margin?
Nami (due to her abilities to control RAIN, the natural enemy of anything microscopic)
Aokiji (if Buggy could pull off the friction trick I mentioned, Aokiji would have to be very, very creative to win)
Now, let's look at fighters from the start of the series to the start of Thriller Bark. I'm ending at the start of that arc because I've decided not to follow it in manga form (it seems like it something which could be very entertaining to watch in anime form without spoilers).
Alvida: Hmm? I don't think he'd have any need to fight someone from his own crew.
Coby: Luffy didn't even break a sweat when he fought Coby. No challenge here at all.
Helmeppo: Again, Buggy would have a gigantic upperhand here..
Axe-Hand Morgan: Again, no contest. Morgan was surely a monster with that arm of his, but Buggy would destroy him.
Jango: Go ahead, Jango.. Try to hypnotize the clown who is spread around into millions of pieces. Easy victory, since Jango would be the one dozing off instead…
Captain Kuro: Kuro had speed, but he didn't have the means to lay waste to large areas instantly, the only huge weakness I could think of for Sub-Atomic Buggy. Again, this would go to Buggy easily.
Don Krieg: Perhaps the poison bomb or just any old bomb in general could delay Buggy, or actually injure him pretty badly. This is assuming Buggy would be naive enough to get close to any bomb Don would lay down. He'd probably want to stay close to Don, who would be trying to avoid the bomb blasts himself. So… unless Buggy was somehow forced to move very slowly or just didn't know about a bomb, he would crush Don Krieg.
Arlong: As badass as Arlong is, who is a great fighter, he has no moves which would be intimidating to Sub-Atomic level. I hate to say it, but.. Arlong would lose.
Mr. 5: I actually think this would be a good fight! Mr. 5, one of the weaker characters by current standards, would actually be able to keep Sub-Atomic Buggy on guard. If he flung random boogers around, some parts of Buggy could get caught in the blasts.. hmm..
Ms. Valentine: What could she do? Honestly? She just changes her weight.. She can't crush Buggy. He could just break up into pieces so damn small that he could avoid her impacts. Sorry, gal.
Dorry and Broggy: Little Garden was so long ago, I hope I spelled their names right. Anyway, They could go insane with their swings and stomps, but all they would do is spread Buggy's particles around. Meanwhile, he'd be able to slip inside them and do some pretty heavy internal damage. I give this fight to Buggy.
Wapol: There is nothing Wapol could do at all. Even if he ate Buggy, he'd be getting more than he'd bargain for.
Bon Clay: Ballet Kenpo would just spread the particles around. They are too small to hit with any force. Sorry, Mr. Swan Shoes.
Mr. 1: Drill all you want. Buggy could get so small that it would have no impact whatsoever.
Ms. Doublefinger: Please.. her fruit is designed to fight big, fleshy things. Sub-Atomic Buggy may be fleshy, but he is far from big. Her spikes would merely displace him and stir him around.
.. you know, I see where this is going. Do I need to go any further, honestly? Nobody in One Piece is currently clever/sharp enough to fight a sub-atomic being on an equal level and they would have to rely on the exploits of their powers. I'm still trying to think of a way for Luffy to defeat a Sub-Atomic Buggy. Gear 2 would seem completely and utterly useless. Gear 3? I've been wondering about it, and if Luffy can do some sort of effective Gigan Stomp or Balloon, then maybe he'll be able to do something. I'm not sure, it's hard to think of a way to combat cunning and clever molecules that THINK.
The big fella to be compared to right now is surely Blackbeard. I think that would be the most interesting fight for Sub-Atomic Buggy (that or Aokiji). I can't think of an instance where Blackbeard's power would disrupt anything Buggy would do. Maybe the black hole/vacuum could be of some use in the fight, but could Blackbeard really nab all of Buggy's particles? I think in a situation like that, we'd see a return of his age old "stab you in the back" tactic that he used on Zoro.
So… I guess the only two who I think would currently be able to defeat a Sub-Atomic Buggy are Ace and Enel. Both use non-matter logia fruits which cannot really be "hit" in the traditional sense and both are capable of burning what they touch. If there is a way for a sub-atomic being to fight these two, I'm not able to think of it at the moment... but with these two indisposed at the moment, would a Sub-Atomic Buggy be free to romp all the way to Raftel without hindrance? Could Shanks, Whitebeard, and the other two Yonkou do anything about it? Could they possibly do something to a microscopic entity?
With Enel hamming it up on the moon and Ace possibly severely wounded (not dead, because this is Oda and Ace doesn't seem like the appropriate guy to kill at the moment), it looks like yes, Sub-Atomic Buggy would be free to do whatever he would want.
Buggy as we know him, just separating his limbs from his body, isn't terribly intimidating anymore given what we've seen the Straw Hats fight recently, however... Sub-Atomic Buggy would be a frightening force. With that sort of potential, combined with Buggy's hateful personality and sharp wits, I think he'd give Luffy a very hard run for his money.