Tanzōryū

Tanzōryū (鍛造流, literally "Forging Method") is the style of magic utilized by Tengu; an ancient art that was given its name from the craft of swordsmithing that Tengu were said to have first developed. It appears to also refer to the method in which Tengu utilize the spells of  as well.

Overview
Similar to that of, Tanzōryū magic operates by manipulating and calling upon the fragmented wills of around them in order to invoke a particular force or effect. However, what makes the Tengu's method so different is the perspective in which it is utilized. If Shinigami use magic as though they were lords commanding their vassals, then Tengu utilize magic as though they were crafting and forging a sword. Simply put, it is akin more so to the art of, in the sense that Tengu are architects; blade forgers.

The first step lies in how Tengu gather together the reishi by crafting the frame of the proverbial blade in their mind. Novices are taught to make out the framework and blueprint of the blade's shape using a series of hand gestures to map out the spell's path. Reishi fills the space made by the hand gestures which trace the flow of energy for the desired spell. After forming the shape, Tengu continue the process as though they were actually forging a weapon; the end result being the creation of a proverbial weapon — specifically, the spell itself — which is then enacted onto the world and its targets. Masters of Tanzōryū can literally materialize the frame of the spell with mere thought, the blueprint instantaneously appearing before them as the spell takes form and subsequently activates. Using this same method, Tengu can even use the Shinigami spells of Kidō through the same process. For example, if a Tengu wished to use the spell, they would create a framework for the spell before them and then unleash the fiery wrath of Sōkatsui onto the victims. Masters of Tanzōryū would instantaneously forge the spell as it strikes the target.

What makes the Tanzōryū so effective is that, unlike Shinigami, Tengu view the reishi around them as raw material; simply that. Tengu do not "tie together" patchworks of reishi, but rather they smelt the reishi down into a single amalgamation of pure energy that is reigned in by the Tengu's will and forged into the spell; just as iron and steel is smelted down as per the process of sword forging in order to craft the weapon. It can even be said that this method rivals the concept of a Quincy's which enslaves reishi, but even slaves can rebel; history has shown that even the lowest classes of society could rebel against their lord. Tengu do not grant them that possibility. They are nothing but raw material for weapons — tools of magic — as they are melted down and crafted into the desired form and shape. It is because of this that Tengu spells are considered nigh impossible to neutralize simply because the reishi can not be torn apart; the reishi do not exist any longer as individual entities patched together by the castor but exist as just a pool of raw power forged by the Tengu's will.