Gate of Babylon

The Gate of Babylon: King's Treasure is a dark red, key-shaped shortsword that connects to the "Golden Capital", the treasury of Gilgamesh, allowing the user to easily access its contents. It connects the space of reality to the vault, opening an "invisible door" that allows for the contents to pass through upon the user's command. The items that pass through the gate form ripples in the empty air as they appear. They can be summoned anywhere, either directly to the users hands or anywhere in the direct vicinity. The rank changes from E to A++ due to reflecting on the ranks of the various contents of the treasury, and it is also once referred to as an EX ranked Noble Phantasm during Fate/Zero due to containing Ea. The Gate becomes more powerful as the wealth of the owner increases, but if the treasury does not contain a wealth of valuables, then it will not be a useful Noble Phantasm. There is probably a Road of Babylon as well.

Holding the key, called Key of the King's Law, Bab-ilu (王律鍵バヴ＝イル), vertically in the air and turning it, the parts around its grip begin to rotate, start to glow, and then settle. It releases a large, labyrinth-like, red pattern that can be seen covering the sky from a great distance away, and then it recedes into a small orb. The key is implied to be able to open any door so long as it has a lock. This Noble Phantasm is the reason that Gilgamesh is of the Archer class, and it was first utilized as such during his first battle with Enkidu. The weapons contained in his treasury become bullets upon his command, making him an archer with the strongest arrows. He generally readies numerous weapons at a time, either just letting their hilts stick slightly out of the gate or letting them levitate in the air behind him. Upon snapping his fingers, the seemingly infinite number of weapons can be fired without pause. They move and take aim at the target according to Gilgamesh's will, allowing him to fire without having to even touch them. Each weapon has the ability to cause certain death to an opponent, and they are shot with enough force to repel a swing from Berserker's large axe-sword. While it is possible to block many of the strikes, to do so without knowing the abilities of the weapons can be seen as suicidal.

He starts out with lower numbers of weapons, but increases the number of weapons fired in a volley depending on the amount of respect or anger he feels towards his target. He uses as little as one or two at first while playing with his opponents, but can easily summon over eighty for a single strike when he is serious. Upon firing them, he can allow them to pierce the ground after striking the target, causing a large amount of destruction with each weapon, or he can instantly return them to the vault faster than Shirou Emiya can even perceive during the Fate route. He utilizes a Noble Phantasm to retrieve any weapons left on the battlefield, instantly dissipating and returning them to the vault. He can leave them out if he wishes, such as when they've been "stained" by striking Caster's summoned creature. The ability to fire the weapons yields an excellent ratio of destructive power to magic energy efficiency due to the cost of prana used to fire the Noble Phantasms as bullets being relatively low. The only real prana usage lies with the Gate of Babylon's activation cost.

He generally fights at long range, though he will wield a single weapon in close combat if he feels confident in his victory. He makes use of the many unknown abilities of the weapons, and constantly switches them to keep his opponent off guard. He can fire at an opponent from extremely close range as well, loosing weapons from above, below, and to the side. Still, he is not a swordsman, so he is easily outclassed if an opponent is skilled at close combat. Against something like Unlimited Blade Works, which allows for weapons to be drawn and fired slightly faster than the Gate of Babylon, Gilgamesh finds himself easily outclassed and overwhelmed when forced to fight in close combat.

Contents
Gilgamesh collected and stored away samples of all the technology that was developed during his age, making his favorite phrase, "I collected all the treasures of the earth", not an exaggeration or metaphor. The treasury contains all of the treasures of the world that he collected during his life, from the finest wine and golden drinking cups to divine mysteries from nearly every legend. As anything can be found within the vault, the amount of wealth within exceeds even his own knowledge. The desires of ancient humans were similar to those of the current age, so their technology, bolstered by the magical energy being alive and well, was not inferior to that of the modern age. The "Instruments of Hope" that people dreamed of were all realized, and because every single case was requisitioned by the King's hand, his collection is even furnished with airplanes and submarines. It also contains all of the original bases for all intellectual properties produced by mankind that originated in his kingdom, making board games and the works of the no more than imitations.

That within are not merely riches, but his collection is the very "origins of human wisdom." That which is missing from the vault would be items produced with completely new concepts by a new human race, and items produced with extraterrestrial intelligence and technology. He is the original hero, so all heroes of various myths are derived from his legend. It may be a paradox, but he, as the original, must possess that which can be handed down as the Noble Phantasms possessed by those later heroes derived from him for that reason. These weapons are technically nameless, the original Prototypes of the Noble Phantasms (すべての宝具の原型) and the common points before they became objects of faith that act as the foundations for their legends.

They are the original models of every legend, myth, and folklore, besides some noted exceptions. He makes references to wishing to obtain Excalibur and Kavacha and Kundala, and he is surprised by Avalon's existence. It is also possible, such as with Vasavi Shakti, that he cannot tell if something corresponds to the treasures in his vault. Karna's legend records that he "has" the spear, but there is no description of it "being used." It does not exist in his eyes due to never having been described, so he wishes to obtain it. The weaponry contained within includes swords, pole-arms, lances, hammers, shields, demonic swords that later made their way to Europe and South America, and a number of weapons unidentifiable to Shirou from sight, all of which form a perfect treasury of masses of unused weapons that simply went to sleep with the king. He owns the treasured swords that saved later heroes and the cursed swords that stole the lives of heroes, and their numbers are approximately infinite. After Gilgamesh's death, the contents were spread all over the world after being passed on or stolen, and the treasure, valued because they were splendid swords, eventually became Noble Phantasms.

Shirou states that the quality of the weapons makes the Noble Phantasms used by others look like fakes themselves. While Cú Chulainn has the Gáe Bolg that became famous, Gilgamesh possesses a weapon that later became the Gáe Bolg, but wasn't famous at the time Gilgamesh owned it. The only item contained in the vault that was not passed on to another user than Gilgamesh is Ea, a sword unique to only Gilgamesh. Shirou claims that even though he cannot see them all, he can feel that their numbers are infinite. If weapons of a previous incarnation meet those that descended from them, such as Gram facing Caliburn or copies facing originals, the deteriorated newer model will always lose.

It contains numerous A rank weapons, capable of piercing God Hand dozens of times to take eleven of Berserker's lives and then piercing him with twenty-three more weapons afterward. Just a single weapon is enough to pierce Caster's strongest shield, and keep any other another Servant on the defensive. The numerous weapons contain various different effects and abilities, allowing him to assault the weaknesses of any Servant. This places him at an advantage over most Servants in combat, such as attacking with a weapon strong against a certain attribute or assaulting a Servant with a weapon they were specifically weak against during life.

Named items

 * Caladbolg
 * Command Spells of an unknown number have been collected by Gilgamesh in the Moon Cell. They are the lifeline of Masters in the Moon Cell Holy Grail War, so it is unimaginable that a Servant would be able to provide a new set to his own Master. While such a thing should shake the Holy Grail War, Hakuno Kishinami rationalizes that Gilgamesh is simply such a Heroic Spirit, proving why he is sealed within the Far Side.
 * Dáinsleif (ダインスレフ) is a demonic sword from the Nibelungen. It is a sword that has been in two myths, with both versions showing its frightening nature. Within the, it is a sword that was part of 's collection of treasure, taken by the clan that killed the Northern European hero, Sigurd. It is a cursed Noble Phantasm that contains a powerful curse of "reparation" to be used on its target, and it also drives the fate of its possessor to ruin and causes them to surely die. Within the , it is possessed by the Danish king, Hogni. He became locked in eternal combat with the king of Serkland, Hedinn, due to the sword's curse, which requires it to always kill a man once drawn and does not allow it to return to its sheath until such is accomplished. While demonic and holy swords carry with them both glory and destruction, Dáinsleif is said to only bring the latter onto its master.
 * Durandal: The Peerless Sword is the holy sword favored by the paladin leader of the Twelve Peers, . It was granted to King Charlemagne of the Frankish Empire by an angel, and awarded to Roland. Appearing in the “Song of Roland", it is a symbol of power splendidly forged much like Caliburn, having been the emblem of the Battle of Roncevaux Pass. It is a dazzling sword that possesses three miracles that allow it to maintain its sharpness even after its possessor's prana is depleted. Though Roland, on the verge of death in battle, had wished to destroy it to keep it from falling into enemy hands, it proved to be completely indestructible. It was featured later prominently in the various legends concerning Charlemagne, eventually becoming a symbol of the knight Roland’s bravery.
 * Ea - Ea is the most powerful weapon inside the Gate of Babylon, and it is the one favored by Gilgamesh. He is able to use a rain of weapons to keep the opponent off-guard while preparing to use it.
 * Enkidu
 * Gáe Bolg
 * Gram (グラム) is the sword of the sun wielded by Sigurd, the greatest hero of Northern Europe in the Völsunga saga. It is a demonic sword of glory and destruction that is the model of Caliburn in the legend of King Arthur and also based on Merodach. Their true natures, the ideas behind their creation, and their souls are very similar. As Caliburn was a "sword stuck in the stone that chooses the king", Gram was also a chosen sword of appointment lodged in the mighty tree of the king of Volsung that was pulled out by Sigurd's father, . Sigurd received the shattered pieces of the sword from his father, Sigmund, and reforged it into a demonic sword capable of killing even a dragon. The legend of Gram and its master, Sigurd, is a tale ripe with glory and destruction fitting the great hero. The later composed Middle Ages Germany retelling, Der Ring des Nibelungen, is a story of a knight equal to the legend of King Arthur with Gram appearing with its name changed to Balmung. It is the greatest of enchanted swords rivaling the greatest of holy blades, and is even equipped with special dragon slaying attributes damaging towards people such as the king of knights who is the incarnation of a dragon. It uses the same ability as Caliburn, a light the burns away everything it touches, that took seven of Berserker's lives.
 * Harpe
 * Houtengeki (方天戟) is one kind of halberd passed down in Chinese culture and the only type of halberd out of many to attain the rank of Noble Phantasm, probably due to the use of Houtengageki (方天画戟) by a famous military commander. It is a polearm with many different uses such as thrusting, swiping, pulling, parrying, and various others. Chinese halberds have a spearhead at the tip of the shaft and a blade attached to the side, and the distinguishing characteristic of a Houtengeki is a unique crescent-moon shaped side blade, the “Moon Fang.” Weapons with only one of these blades are called Seiryugeki. It is said that a great deal of skill is needed to handle this weapon, though its versatility and ease of use once mastering it allowed for it to be used to serve the appropriate role for any type of combatant. Its use eventually went out of favor as different dynasties rose and fell until it was revived during the Song Dynasty as Houtengeki.
 * Merodach: The Original Sin is the originating sword that eventually led to the legends of both Gram and later Caliburn. The word Merodach is a form of the name of Marduk, the patron god of Babylon.
 * Potion of youth
 * Sha Nagba Imuru: The all-knowing, all-powerful star is the Noble Phantasm owned by the child form of Gilgamesh in the Fate/hollow ataraxia card game. It allows him to view some of the cards in the opponent's hand and deck. It is unknown if either form of Gilgamesh possesses it outside of the card game.
 * Vajra (ヴァジュラ) is a weapon appearing in the of ancient India. It was a weapon crafted by Tvastar, the maker of divine instruments, using the bones of the sage, Dadhichi. It became symbol of divinity of, the god of lightning, and the indestructible diamond pounder (金剛杵) weapon carried by the gods of Buddhism. It was held in one interpretation to be a manifestation of Indra’s lightning, which is supported by its deceptions as a golden projectile and its appearance unbefitting of a conventional weapon. Vajra was initially known by its proper name of Vjaya when Indra was first introduced to India as a phenomenon that spread from the . Along with Indra, whose name changed to , his divine symbol also had its name changed and became known as Vajra after the age of Buddhism as India's main religion began. It is a simple weapon that can only be shot only once for a fixed B+ rank damage separate from the user's prana supply.
 * Vimana

Unnamed items

 * Axe, scythe, and scimitar with the ability to change their path after being avoided by the target, allowing them to turn around in mid-air towards the target at a speed that allows them to match the pace of a jet.
 * Cooking items - The treasury contains meat that multiplies in proportion to how much is eaten, hydra meat, a fully automatic cooker capable of processing hazardous food like the hydra meat, and a tablecloth capable of manifesting any food the user chants. It also contains seasonings and herbs, but he notes that none could make the almost-poison cooking of Lancer palatable. There is an herb that can prepare the stomach for such a meal, but it causes permanent upon consumption.
 * Curtain of night (夜の帳) is mentioned as something that could be used to counter Gawain, possibly affecting his Numeral of the Saint skill.
 * Defensive armament that protects against the Multi-Dimensional Refraction Phenomenon that is capable of stopping Tsubame Gaeshi.
 * Giant sickle able to cleave a weapon enhanced by Knight of Honor in a similar manner as Gae Dearg.
 * Golden axe, lance, drill-like weapon, and swords similar to Enki utilized in close combat in Fate/Extra CCC.
 * Golden armor that he often wears, though it is unknown if it is one of his Noble Phantasms or normally stored in the vault. It is shown to be able to withstand multiple B rank attacks and the rebound of Merodach. It improves his Magic Resistance and grants protection against petrification.
 * Invisible sword like Invisible Air.
 * Machine guns, nuclear warheads, and other weaponry from ancient India that were previously equipped to Vimana. They were removed and stored within the vault.
 * Mirror shield used to effortlessly repel strong magecraft.
 * Poison tasting Noble Phantasm
 * Retrieval-based Noble Phantasm that returns weapons to the vault no matter how far they travel.
 * Sickle that drains away prana and deals damage while passing directly through flesh and armor without causing any actual physical damage.
 * Swords and spears capable of piercing through mountains.
 * Swords and hammers larger than a person.
 * Sword of ice that freezes the space that it cuts, allowing it to cover the target in ice even if they manage to dodge the actual strike.
 * Ship of light (光の船) that allows him to travel faster than the speed of light. It allows him to instantly return after he is sent to the edge of the Moon Cell's Imaginary Space hundreds of lightyears away. When the feat is questioned, he mentions that it is obvious that he would have a Noble Phantasm corresponding to a technique that sends the target to the edge of space, as his vault holds the origin of human wisdom.
 * Three-edged sword able to arc behind the opponent to attack them from an unguarded position.
 * Wine, "the king's wine" as claimed by Gilgamesh, contained in a set of wine bottles made of heavy gold that are inset with sparkling gems. Rider believes that it could not be brewed by human hands, asking if it is a "drink of the gods", to which Gilgamesh affirms by boasting that "Whether wines or swords, only the best is stored in my treasury."