Spirit Arms

Spirit Arms are a type of Dwarven tools and weaponry. They are powered by the user's own spirit, acting like their personal magic wand of sorts.

Since dwarves could overload and blow themselves up when channeling spirits unassisted due to their mithril hair, a catalyst is required for them to use magic. A spirit arms is made by engraving complicated runes into catalysts and combining them. It has a ‘core catalyst’ and by synchronizing with it, the dwarf user can cast many different types of magic.

By making a spirit arms with interchangeable parts and transformable structure, they can also change the combinations of runes they can cast. They can even cast multi spells at the same time, which was an ability originally exclusive to the Elves.

Appearance
Since the spirit arms is made as a personal tool to each and every individual users, it can take any forms. Some known examples are:


 * Nýi Tilvilg: Large mallet
 * Lóni Drauvnil: Giant sword, giant robot
 * Unnamed Dwarf: Ball
 * Veig Drauvnil: Giant sword, giant robot
 * Kuhaku, Chlammy and Fiel: Giant robots

Background
The dwarves have been creating spirit arms to augment their magic throughout their history. They made these tools with their intuition and imagination, hence no blueprint or design is necessary. A dwarf was seen creating one just by hitting the raw materials with a hammer. Not even dwarves know how it works.

The power and function of a spirit arms depends on the creator's craftmanship. The most powerful spirit arms are a pair of giant robots made by Lóni and Veig, armed with an inactive (fossilized) divine spirit or materialized concept that can perform conceptual rewrites. However, this game-breaking power is only used to enlarge females' busts, in which Sora dubbed as "the greatest waste of potential ever".

Trivia

 * Nyi does not possess a dwarf's intuition, therefore she assemble her own spirit arms by combining discarded runes with elven mechanisms.
 * Jibril could not use spirit arms due to the Flugels having immense amount of spirits. The orihalcum catalyst would be vaporized the moment she channel her spirits into it.
 * As elves don't use tools, their affinity with spirit arms is exceptionally poor. When testing their spirit arms for the game against Vieg, Fiel caused the robot to fall over head first into the ground the moment it starts, even when Sora described that operating the machine is like "moving their own body at will".