The Six Forms: Rokushiki
Six abilities is all it takes to make you "superhuman." Just SIX. When you think about the versatility of those half-dozen styles, though, it becomes apparent that turning yourself into a living weapon doesn't require a Devil's Fruit.
The origins of Rokushiki -- that is, the "Six Forms" of Cipher Pol #9 -- are unknown of this time, but judging by a given flashback, it existed in some form twenty years ago, and is still in common use today by the Cipher Pol agents of the Ninth cell. To a lesser extent, four forms makes up Yonshiki, which is used by Nero of the group, but with considerably less effectiveness.
Each of the Six Forms is defined strictly, but is by no means set as a singular form: "branch" techniques, such as Rankyaku Sen and Tekkai Sai exist, and it is possible that each member of CP9 has specialized in a given technique, as shown by their usage of branch techs. Below, you'll find more detailed information on each of the Six, as well as the referring quote from CP9.
Users
Nero (uses Yonshiki, Four Forms)
- Former CP9 (20 years ago)
Tekkai
"We've trained our bodies such that we can turn them into 'Iron Carapaces' if we so choose..." - Blueno, CP9
Tekkai, or "Iron Mass," is a simple concept: Harden your body to the consistency of iron or steel, and thus resist any blow. Simple, but also deadly to a normal foe who can't overcome iron, this Form actually combines well with Soru (as used by Blueno) and one's physical features (such as with Fukuro).
Tekkai Rin: The user, while in movement, crashes down upon the ground with the affected Tekkai body, which is then vaulted again and again in a wheel-like shape. "Rin" means "Ring" or "Wheel," fittingly enough.
Tekkai Sai: While in mid-air, the user pivots his body and crashes down with a sudden punch using Tekkai's force, crushing the enemy and surrounding area -- the term "Sai" means "to Crush."
Tekkai Gou: In a stationary position, the user achieves the "perfect" Tekkai (or at least the strongest one we've seen), and negates an attack's force. This is the iffiest of the Tekkai branches, arguably, as "Gou" didn't seem to have much of an effect other than to stave off defeat for a few seconds longer. "Gou" means "Strong/er/est."
Tekkai Dama: Apparently deriving its "spherical" name from Fukuro's shape, Tekkai Dama is a combination of Soru and the CP9 member's rounded shape, whereby Fukuro charges forward using Soru, spins, and crashes into the enemy like a bowling ball.
Tekkai Wutsugi: A counteractive Tekkai, acting somewhat like an Impact Dial as I understand it. Its Kanji means air wood.
Geppou
"... one can also kick the air to float..." - Blueno, CP9
Imagine being able to bounce off of nothing but air! That is Geppou, or "Moon Walk". The CP9 have put this to good use in battle, most especially by Califa, by evading and lunging with unparalleled talent. Though no branch techniques for Geppou have been introduced thus far, it remains used and useful, and perhaps we'll see a secondary form later on.
Rankyaku
"It is possible to be fast enough to cause 'kamakaze'..." ~ Califa, CP9
Question: When you don't have a sword, what do you use to slice and dice? Answer: Rankyaku, or "Tempest Leg." The term "kamakaze," or "Scythe Wind," refers to a "phenomenon of rapid movement" that cuts open a passage of air (also known as "Kamaitachi"), and Rankyaku shows that by proving capable of breaking open skin, buildings, whatever. This is the primary offensive technique of the Six Forms, it seems, because it can be both a close- and long-range attack.
Rankyaku Sen: Nero's apparent specialty, the Rankyaku Sen distributes the force of a Rankyaku across a wide distance in a line-shape ("Sen" means "line"), which can be quite fast and very powerful as a piercing weapon rather than a slashing one.
Rankyaku Hakurai: The meaning of this move is unclear. What I can see is that the Hakurai's -- "White Thunder's" -- trajectory is diagonally downward, and it may well be more powerful than normal. That's what I'd assume.
Rankyaku Ran: Meaning "Chaos," Rankyaku Ran lashes out with dozens of Rankyaku strokes from all angles, making it extremely difficult to dodge or block, done from above the enemy.
Rankyaku Amanedachi: Amanedachi is a move that only a Giraffeman could perform easily. By extending his limbs in a sweeping kick, the centrifugal force of the movement is therefore multiplied, slicing open a massive area with equally massive force. Amanedachi means a "Wide Sunder" or "circular cut."
Rankyaku Renge: Renge translates to "Lotus," which seems to fit this spiraling frenzy. It might be one of two things from the panel we see it in: Perhaps a series of kicks like "Ran," or maybe using Kumadori's hair as a weapon. Confirmation may have to wait for a few anime episodes to progress.
Rankyaku Lupus Four: A technique unique to Jabura, Lupus Four rains down four hopping manifestations of wolves' heads.
Rankyaku Roudan: The Rankyaku Roudan ability (Roudan translating to Dragon Split) strikes up with two feet to deflect an enemy's slicing attack.
Rankyaku Neji Hakujin: Neji Hakujin is a spiraling version of Rankyaku that, unlike Amanedachi, may be performed quickly and cleanly. It has as wide an area of effect as the user's limbs.
Rankyaku Shuriken: The user (in this case, Kaku) whips out his leg and releases a series of sharpened blade-Rankyaku attacks.
Rankyaku Hyoubi: The user swings out and creates a vortex of swirled air resembling a leopard's tail, which alludes to the name ("hyou" is "leopard").
Soru
"With leg strength explosive enough to seemingly cause one's body to 'disappear'..." - Blueno, CP9
Soru, which means "to Shave," has the virtue of being the only part of Rokushiki that has been explained: To stimulate unseeable movement, the ground is kicked ten or more times in an instant, thus launching the user forward. This facilitates great offensive and defensive gestures, being similar to (but possibly surpassing) Kuro's Nukiashi, and allowing for sudden lunges and dodges. When combined with Shigan, it is absolutely lethal. The verified specialist of CP9 at Soru is Fukuro.
Shigan
"A bullet isn't needed to pierce the human body." ~ Kaku
The fifth Form, Shigan (Finger Gun), is perhaps the most unusual. Just by extending their finger, a CP9 is able to PIERCE the human body like a bullet from a gun, stabbing into the target with great force. It isn't known HOW this is done, yet; it is speculated that a localized form of Tekkai is used to harden the finger, but there's no real way to tell for sure yet. Oddly enough, Rob Lucci uses a five-fingered Shigan, though a variant name has yet to be released.
Dugong: Usually Shigan is used with just the index finger, but Dugong -- a specialty of Fukuro, apparently -- uses the entire fist as a "bullet." Rather than relying on a narrow space to pierce, the CP9 member instead would use his entire fist to crush. Dugong (literally Jugon) means "Beast Majesty,"
Dugong, Fukuro-dataki: Using the same principles as Dugong, Fukuro-dataki strikes from many angles using (apparently) the agility-based Forms to do so. The kanji, according to resident One Piece expert Stephen, means "bag-beat" usually, but with the first Kanji replaced with that of "Owl," creating a pun on Fukuro's name (Fukuro meaning owl).
Shigan "Q": Kumadori is a master of the Seimei Kikan, the Life Feedback talent he acquired through intensive training. Life Feedback affords him full control over every aspect of his body, and it seems that extends to anything he holds, as well; "Q" turns his monk's staff into a piercing, lengthy Shigan tool.
Shinaru Shigan Whip: A bending thrust of the single Shigan.
Jusshigan: A Shigan performed with all ten fingers lined up in a circular pattern.
Gekkou Jusshigan: A descending version of the above.
Shigan Ouren: Multiple stabs of a single finger at lightning-speed.
Kami-e
"... But there's no art to being hit..." - Blueno, CP9
Kami-e, the "Picture Paper" Form, was the least seen until the Fukuro fight. In fact, I think we've only seen it a ciuple of times, at most. Well, whatever; this one is still a Rokushiki. The principle behind the move is to move so swiftly and acutely that the opponent cannot hit you -- you float about like a piece of paper in the wind.
Kami-e Slime: Kami-e as displayed normally makes it look as though the user is fluttering like a piece of paper. Slime, though, makes the user's body like putty, making great twists, bends, and slouches very possible.