Fusion Sword

The First Tsurugi is the collection of six swords, and their single combined form, used by Cloud Strife as his primary weapon in Final Fantasy VII: Advent Children, the sequel film to Final Fantasy VII, as well as in a handful of spin-off titles. As a set of six swords the First Tsurugi blades come in a variety of shapes and sizes and are thus suited to a variety of combat situations, and can combine to form a single large sword similar in size and function to Cloud's famous Buster Sword. This variety of uses and blades gives the First Tsurugi a wide array of uses by combining and seperating different blades to suit the fighter's needs.

The film's creative designer Takayuki Takaya has stated the individual swords have no names, and no other names for them have been put forth by the creators other than "First Tsurugi" to refer to the entire set, and the term "fusion swords" which was used during development. However, the blades have become known in the fan community as Vigilante, Vendetta, Merciless, Avenger, Ascalon and Sidewinder.

The Swords
The First Tsurugi is composed of six separate swords that assemble into one large sword. The First Tsurugi in its various states of combinations serve as Cloud's primary weapon in the film. The swords of the First Tsurugi are not named in the movie, but they otherwise can be distinguished by their distinctive appearances and functions. The First Tsurugi consists of one main blade, one hollow blade that serves as the front edge, two identical (but asymmetrically opposite) blades that form the back, and two identical (also asymmetrically opposite) smaller blades that attach to the sides.

The swords of the First Tsurugi in its disassembled state are usually stored in racks inside the special compartments (three racks per compartment) on both sides of Cloud's motorcycle, the Fenrir. In addition, Cloud wears a harness on his back which he carries the swords in. Since this harness is never shown fully occupied, it is possible that all six swords can be carried by Cloud at once. Cloud is also able to perform most of his Limit Breaks with the various swords, although it is unclear how the number of blades locked into place corresponds to the strength and ability to use those Limit Breaks, if the number of blades affects them at all.

Main Blade
The main blade resembles an exaggerated two-handed sword in its shape and appearance, though Cloud usually wields it with only one hand, invariably his right one, despite its apparent size and weight. It consists of a long hilt wrapped in a red material, a distinctively large handguard which the other swords are locked into, a wide length of blade, and an equally long but thinner length ending in a point. The main blade is the only sword among the six that is double-sided, and is somewhat similar in silhouette to Cloud's weapons "Heaven's Cloud" or "Crystal Sword".

The main blade has two forms. In the first, the appearance is as described above, with the blade of the sword appearing to be one solid length of metal except for the transition between the wide and thin halves. In the second, the blade is pulled in two lengthwise; the edges are locked apart and a complex inner portion of the sword is visible, giving the blade an appearance not identical to but reminiscent of Cloud's Apocalypse sword.

The main blade, by itself and as other swords are attached, is Cloud's main weapon, although he uses the other blades sans main blade as well. In addition, Cloud is shown to be able to use his Blade Beam Limit Break using only the main blade.

Hollow Blade
The hollow blade does not have an inner core as expected for a sword. Rather, it is essentially (though not exactly) a thick sheet of metal folded in a V-shape when looked from above, the edge of the sword being the bottom point of the V, with its lower one-third of its length wrapping around a red double-hilt. The hollow blade is locked onto the front edge of the main blade, where it snugly covers that entire edge of the main blade, and its own edge serves as the striking point for the assembled sword. It is this addition that turns the First Tsurugi from a symmetric shape to the distinctive Buster Sword appearance.

The hollow blade, while not Cloud's primary weapon, was perfectly capable of serving as such when Cloud was deprived of the main blade in the battle at the Forgotten Capital against Yazoo and Loz. Despite its lack of an inner core, it is strong and sturdy enough to deflect and block bullets from Yazoo's Velvet Nightmare handgun and Loz's physical attacks. After regaining the main blade, Cloud uses the hollow blade as an off-hand weapon. He also ejects the hollow blade from the completed First Tsurugi as an off-hand weapon during the fight with Sephiroth, where it again demonstrates its strength by fending off Sephiroth's Masamune as well as slicing up falling debris.

Back Blades
The back blade are identical long swords, mirror images of each other, with one edge completely straight and the other a saw-tooth pattern, and a long black hilt for each. These two swords are attached to the back of the main blade, on both sides of the main blades back edge, with the saw-tooths pointed forward toward the hollow blade. The addition of these two swords completes the trapezoidal silhouette of the First Tsurugi.

The two blades were used by Cloud in the fight against the summoned Bahamut. One was an off-hand weapon to complement the connected main and hollow blades; the blade's saw-tooth edge is the striking edge, and Cloud wielded it until he attached it to the main blade in preparation for the Braver limit break. The other blade was carried on his back harness, until it was attached in the same battle in preparation for the Climhazzard Limit Break.

Side Blades
The side blades are identical, mirror image dagger-like swords, though they are still quite long. They are singled edged, with a gear-like mechanism between the hilt and the blade that allow them to fold up like a switchblade. It is in this folded form that the two sides blades are locked onto the two sides of the assembled sword, with their edges turned forward toward the main blade at the front of the sword. In addition, one of the two blades can be quickly ejected from the assembly if needed, providing Cloud with a needed off-hand weapon as was the case in the highway battle and his battle with Kadaj.

As part of the assembled First Tsurugi, the side blades do not appear to have any vital function like the rest of the swords, possibly only adding extra weight, and therefore force, to strikes, and providing a decorative appearance. The side blades may also possess some sort of locking mechanism designed to hold the other blades in place or be meant to cover the hilts of the other blades to the same effect. It is also entirely possible the blades are merely for convenience so as to provide an efficient secondary weapon without compromising the strength of the assembled construct, as Cloud shows. Another possibility is that they might just be there to add more strikes onto Cloud's Omnislash Version 5 Limit Break.

Completed First Tsurugi
As mentioned before, with the locking of the five auxiliary blades into the main blade as detailed in the diagram, the completed First Tsurugi takes on the distinctive appearance of Cloud's iconic Buster Sword. Unlike the Buster Sword, which contains two obvious round slots for Materia to be inserted, the First Tsurugi does not have any similarly obvious placement options.

The First Tsurugi, much like the Buster Sword, is primarily a crushing weapon, not necessarily a slicing weapon as a nodachi such as Sephiroth's Masamune would be, though Cloud is perfectly capable of slicing through even concrete with it. Although its appearance is as stout and sturdy as the Buster Sword, Cloud does not demonstrate any more difficulty carrying and wielding it with one hand than he does using only the presumably lighter main blade by itself.

In addition, the First Tsurugi does not appear any stronger or weaker than Kadaj's Souba (a tasseled double-katana) or Sephiroth's Masamune, neither damaging nor being damaged by repeated full-strength edge-to-edge blows between either, which would certainly damage a real sword's edge if not outright break one of or both of the swords. However, it is demonstrably capable of cutting through Yazoo's Velvet Nightmare gunblade and Loz's Dual Hound pile bunker, which the main blade alone was not.

Omnislash Version 5
Omnislash Version 5: zwbEHsCcIF4 In Japanese, called "Choukyuu Bushin Hakazan Version 5", Cloud's final limit break in Advent Children is a fast succession of six slashes using the six swords of the First Tsurugi one time each. It is significantly different from the Omnislash in the original game, which only used one single sword for a longer sequence of fifteen slashes. Within the film, the technique is only performed on Sephiroth, who is floating in mid-air; it is unknown how the technique would look performed on a grounded target. Omnislash Version 5 is performed according to the following steps:


 * 1) The completed First Tsurugi is fully disassembled in an instant, the five auxiliary swords ejected upwards from the main blade in a circle around the target. The main blade itself flies to float above the target as the other auxiliary swords circle them.
 * 2) The performer flies forward and grabs one of the five auxiliary swords, dashing towards and slicing the target with it.
 * 3) The performer repeats this process four times, slicing the target with each auxiliary sword. Each time the performer takes hold of another sword, a glowing copy of themselves is left in their place holding the previous sword.
 * 4) Finally, the performer flies above the target, takes hold of the main blade and descends for a final attack. They unleash a shockwave as their strike connects, dispersing the glowing copies holding the auxiliary blades. The performer lands on the ground surrounded by the five auxiliary blades, and the main blade falls into their hand a moment after.

Concept
In the Reunion Files for Advent Children, Nomura made a joke about choosing to give Cloud six swords due to the jokes that had been made over the Buster Sword's size; "people joked that since Cloud went with size last time, he should go with sheer numbers this time". The original idea was for Cloud to have six individual swords which he would carry on his back, and the concept eventually was modified for six interlocking swords. At the time the concept was originally put forth, it was thought impossible for the idea to actually be executed, but proved to be an interesting twist to the story and its fight scenes and so was put into place. Prior to the sword being designed, Cloud's scenes were shot with him still utilizing the Buster Sword, as seen in various shots of the movie's early footage.

Dirge of Cerberus -Final Fantasy VII-
Cloud wields the First Tsurugi's main blade during the assault on Midgar, and uses it to battle Rosso the Crimson.

Dissidia Final Fantasy
Whilst wearing his alternate outfit from Advent Children, Cloud wields the First Tsurugi's main blade as his weapon, and wields the completed assembly as his weapon in EX Mode. He is also able to perform a variation of Omnislash Version 5 in any outfit. For purposes of gameplay (as Cloud does not usually have access to the First Tsurugi), the attack involves Cloud dashing past a mid-air opponent five times, then leaping up and diving down for the final strike, using the same weapon for all six strikes.

Kingdom Hearts II
Cloud's weapon in Kingdom Hearts II is the fully assembled First Tsurugi, although it is wrapped in bandages like the Buster Sword in the first Kingdom Hearts game. Cloud never fragments it into its individual swords, although he presumably could. He uses it in all his battles throughout the game.

Etymology
"Tsurugi" is a Japanese word for "broadsword", also used to refer to Chinese swords, and used in the west to refer to a type of Japanese straight-bladed double-edged sword no longer in use. The mythical Kusanagi-no-Tsurugi was one such type of sword. A literal translation of First Tsurugi would thus be "First Sword".