Sylph

Sylph or otherwise known as Fūjindō (風神道, Way of the Wind Gods) is a Dōjutsu and Ninjutsu technique unique to Akari Murakami and rooted in her Saishū Ketsugan. It gives her the ability to control nothingness by using Wind Release to conjure into her vision vacuums known as Sylphs strong enough to suck things out of existence.

Description
As stated before Sylph allows Akari to conjure these special vacuums into her vision. Once conjured they can be manipulated and controlled in many ways. Akari usually uses the ability to shape the sylphs into weapons that does damage to the target's existence rather than physical body to slowly erase them from existence with every strike or shields to suck an oncoming attack out of existence. Akari also uses this control to decrease the power of a sylph to the level of a normal vacuum to allow her to create and use vacuums.

Sylphs can be used in one of three ways outside of simply being conjured into her vision. These three ways are used through a process called inscription: a way of using Fūinjutsu to seal the vacuums into a target to transfer the ability of nothingness into the target.

Sylphs can be used in one of three ways outside of simply being conjured into her vision. These three ways are used through a process called inscription: a way of using Fūinjutsu to seal the vacuums into a target to transfer the ability of nothingness into the target.

The first and Akari's most used way is Self-inscription. This allows her to control her existence to allow her to fade in and out of reality. Unlike how it is done through Kōga-ryū, this deletes her existence rather than simply having it fade away. In this way nothing remains of her, not even the idea of her existence. When she uses Self-inscription everyone who knows her will forget about her and everything she has ever done will be undone until her existence is restored. Also, unlike Kōga-ryū she is able to delete parts of her body from existence whether it be a limb to pass off as a cripple or a vital organ to erase her need for one. Erasing an organ in this way is much harder than a limb and the effects are merely temporary.

The second way of using inscription is to inscribe the vacuum into a target within her sights. This works much like the original way, but unlike the original way it is more like sealing the target out of reality instead of deleting it. This allows her to use Sylph in much the same way as Kamui: using it to seal and ejecting things to and from the realm known as nonexistence. The last way is inscribing it into the Saishū Ketsugan itself. This allows the dōjutsu to become something like Otohime's Mind's Eye in that the eye can perceive what Akari isn't aware of allowing to perceive nonexistence. There are many ways of using this for example as a danger sense to alert her to attacks that she isn't aware of or to keep track of what she has sealed out of reality.

Similarly to Amaterasu, the sylphs are invulnerable to anything that targets the vacuums themselves so it can't be destroyed by any normal methods. The chakra that composes it is another matter. Techniques that focus only on chakra like the Chakra Disruption Technique or a Fūinjutsu that focuses only on sealing chakra are able to destroy the vacuums.