Ultima Weapon

The Ultima Weapon is a Keychain for Sora, Data-Sora, Riku, Terra, Ventus, and Aqua's Keyblades introduced in . It is one of the most powerful Keyblades, and requires an incredible amount of effort to obtain in each game. Unlike other Keychains, each game's version of the Ultima Weapon has a different design, and shares only the name and the phenomenal quality of its stats.

Design
The Ultima Weapon Keyblade is named after the in the Final Fantasy series. The Ultima Weapon is typically shown within the Final Fantasy series as a long sword, with a glowing blue/white blade and a golden handle. It is usually the strongest weapon for the main protagonist in the games it appears in.

The Kingdom Hearts version of the Ultima Weapon is strongly reminiscent of the Dream Sword, but is wrapped in an ornate gold in a pattern slightly reminiscent of fish bones. The teeth of the blade are a golden version of the crown charm Sora wears, and the Keychain token, attached to the blade by shimmering thread, is a gilded, used throughout the series to refer to a complete being, instead of a Heartless or Nobody. It also bears one heart just above the guard and another just next to the crown making up the teeth of the blade, both of which are present in the Kingdom Hearts II version. In the game, the blade's size is smaller compared to the hilt, compared to its design in the official artworks; this resembles a real-life section of a sword known as the tang (the section of the blade that is mounted into the handle). Small circular ripples and bolts of light are emitted whenever Sora strikes a target with it. This version is also used in Kingdom Hearts Chain of Memories and Kingdom Hearts Re:coded. In Kingdom Hearts Re:coded, the names of its upgrades in the Japanese version use letters that, when appended to the end of a name, typically indicate greatness or superiority: A, S, X and Z. In the English version, the names instead use the mathematical symbol for "greater than", and each upgrade adds an additional "greater than" symbol.

The Kingdom Hearts II version retains most of its Kingdom Hearts version elements, except for the colors (blue, white and gold), the crown-and-heart keychain, and the Dream Sword. It also includes many more crowns into its design, including one at the tip of the blade, near the crown "teeth", two making up the guard, three in the chain, and the aforementioned combination of a crown and the original heart Keychain as the token. The blade has been segmented into two "halves" (possibly symbolizing Sora and Roxas) representing a roman numeral for 2 (II).

The Kingdom Hearts Birth By Sleep version has elements from both previous Kingdom Hearts games. Its style is similar to the Kingdom Hearts version, but its color scheme is similar to the Kingdom Hearts II version. It also uses stars and the Wayfinder design instead of crowns and hearts. It is mostly a pale, luminescent blue with white and gold. The teeth and Keychain are a blue Wayfinder, similar to Aqua's, with the original heart in the middle instead of the Terra's Mark symbol.

The Kingdom Hearts 3D: Dream Drop Distance version has the design similar like the Kingdom Hearts version with minor changes. The color scheme is somewhat a combination between the first and second Kingdom Hearts games, as it has yellow on the blade connector, and the teeth and light blue color on the guard and the filigree ornament. The teeth is a Spirit Dream Eater's emblem within a crown. The keychain is a variation on the Kingdom Hearts II heart and crown design, except with the heart above the crown, as well as a pair of white wings behind it.

The Kingdom Hearts III version has a color scheme of silver, red, and dark grey; two hearts adorn the weapon, one engraved into the hilt and the other at the base of the teeth. The blade has been segmented into three tines, representing the Roman numeral for three (III).

Kingdom Hearts II
An Energy Crystal is required to reduce the Orichalcum+ required for synthesis, as there are only 7 in the game. As Serenity items are part of the recipe, they cannot be used to upgrade it.

Gameplay
The Ultima Weapon is an extremely powerful Keyblade with an impressive reach. It is generally the most powerful Keyblade in each game that it appears, with balanced stats near or at the maximum for that game. In Kingdom Hearts II and Kingdom Hearts Re:coded, the abilities attached to the Ultima Weapon are some of the most useful in the game. However, there are some Keyblades which exceed the Ultima Weapon in a specific stat, such as Strength, while being inferior in other stats, such as Magic. In Kingdom Hearts Birth by Sleep Final Mix, however, the Ultima Weapon is actually inferior to the Master's Defender and Royal Radiance across the board. In Kingdom Hearts III, a LV1 Ultima Weapon has a lower Magic stat than most other Keyblades, but when raised to LV10 it is only second to the Classic Tone.

Other appearances
Both the Kingdom Hearts and the Kingdom Hearts II versions of Ultima Weapon were released with three other Keyblades in a special Play Arts Figures accessory set, Play Arts Arms.

Through the use of a cheating device, textureless versions of the Ultima Weapon can be obtained in Kingdom Hearts II. These are the "Edge of Ultima", a version of the original Ultima Weapon with a glitched appearance, and the "Detection Saber", a second copy of the original as well, except slightly larger. When these Keychains are accessed in Sora's Items menu, no picture of the Keyblades are shown, only map icons.

Kingdom Hearts 358/2 Days
In Kingdom Hearts 358/2 Days, Ultima Weapon is an Ability Panel, instead of a Keyblade, that raises the Strength of the user's equipped weapon. It can be redeemed for 255 Challenge Sigils at the Moogle Shop.