Kahenkei (E'Athanata)

is the kekkei genkai of the Shakunetsu clan. It allows the user to absorb an existing flame they did not create and break it down into Yin Chakra and Yang Chakra, allowing them to mix it with their own chakra and boost the power of their own Fire Release Techniques. Because of this, it is classified by some as a form of Yin-Yang Release.

Background
Those who inherit the blood of this clan have almost featureless, red eyes. When activated, the user gains a distinct, fiery red aura, and their stance and gate becomes more bestial.

Abilities
The primary ability of Fire Shaping is that the user can break down fire, both chakra made and natural, into the natural energies of the universe, specifically yin and yang chakra. When they do this, the fire swirls around their body, giving them a fiery aura, before entering their body through their mouth. As they "eat" the fire's energies, they direct the energies through their stomach before leading it into their chakra pathway system, which is the network of vessels that carry chakra. From there, the user can mold the new chakra with their own chakra so as to empower their jutsu.

Drawbacks
This technique has a major drawback, however. As the technique focuses on breaking down fire into it's most basic components, the user must have excellent chakra control. If the user's focus ever slips, or their chakra control isn't strong enough to precisely separate the yin chakra from the yang chakra, they risk the possibility of the flames remaining as fire while inside of their body, where the fire could potentially do major bodily harm. Though this drawback would seem to make learning the technique fairly pointless, the Shakunetsu clan is known for having precise chakra control and for living in hot environments, allowing them to perform this technique with a lower chance of harming themselves.

As an additional drawback, the user must make sure not to attempt to mix their own chakra with the fire's chakra directly, as this could cause the two to mix improperly, creating a new flame within the user's body. To help avoid this, the user must make sure to detour the energy into their stomach, as the stomach is the source of energy in the body, often referred to as the "sea of chi" by monks and sages. It is essential that the new chakra pass through the stomach, as if the fire formed by an imbalance of the two chakra were to occur in the heart or the lungs, the effects could be fatal. A physical motion may help focus the energy flow in the path through the body, such as by touching their lips, then dragging their fingers down their throat to guide the fire to the stomach.

An additional problem, though not necessarily a debilitating one, is the fact that the large amount of chakra can also disrupt the body's natural balance of yang and yin chakra, as fire chakra contains a balance of 2 to 1, respectively. This imbalance would be considered a drawback by many, however, as most users of this technique use it to empower their own Fire Release techniques, which use the same ratio, the imbalance is quickly removed from the equation by the use of a Fire Release technique.

Trivia

 * Sometimes the users of Fire Shaping use hand seals when activating the ability, though it is also able to activate without any seals. Most commonly, no seals are used.