Gi Magic is a Caster Magic and Holder Magic as well as the antipode to Sword Magic. It allows the user to improve and weaponize their body with gis to improve their body's performance with martial arts.
Gi Magic, much like that of Sword Magic, has two sides. Its Caster Magic side revolves around the creation of these gis while the Holder Magic side involves the implementation of the gis.
When creating a gi the user surges their magic power outward to envelop themselves in a Magical Aura that begins to siphon the etherano around the user from the atmosphere and into the user's magic origin. The ethernano imprints itself with the unique information of the user's magic origin before returning to the Magical Aura to transfer the information to it. Within a short period of time the information will begin to give the gi a defined shape and form of the user's gi that is a mirror of their magic origin almost as if the user is wearing their magic origin.
Next is the Caster Magic side. As this process is essentially changing the essence of their magic from one that stems from the mind into one that stems from the body the nature of their magic power becomes more closely related to ki than to normal magic power becoming an extension of their physique rather than an extension of their mind and will. This allows it to be better suited for martial arts than normal magic power. It can bring out the latent potential of a user to allow them to break their physical limits resulting in a considerably augmentation of their physical abilities that can extend past what even activating their Second Origin can provided if used in the right hands.The ki natured magic power can also be released and shaped into various body parts that are usually larger than their genuine counterparts and better in every way. These magical limbs acts as an extension of the body rather than the user's physique like the ki natured magic power itself. In general, these limbs are used for giving the user an edge in a hand-to-hand fight.
Apart from these two functions and much like Sword Magic, Gi Magic can be used to perform a variety of attacks. They can use this special magic power to extending the reach of limbs to make them a threat to mid and long range fighters that would normally have an advantage over them. They can also modify the magic power to allow them to infuse their gi or body with various elements to give them access to a larger variety of martial art techniques and makes Elemental Martial Arts a breeze. Premade gis, that is gis manufactured by a company instead of manifested from a magic origin, are limited to what lacrima was placed in it. For example, a gi with a Fire Magic lacrima can only combine the body with fire. In both cases unlike Sword Magic, their use of the elements are limited to short range use and can't be used for long range. Typically cloaking a body part in the element, transforming the body into an element, or enchanting it with its attributes. At best users of Gi Magic can perform mid-range attacks, but that ability is limited to masters.Lastly, serving as the antipode to Sword Magic's ability to manipulate sword, Gi Magic allows the user to use their ki natured magic power to freely control their anatomy. They can manipulate and generate any part of their body as they wish allowing the user to turn their body into a make-shift weapon much like users of Slayer Magic. Some can even alter their biology to gain traits of other species, but this puts a huge burden on the body so it isn't done often.