Kitsune can wield, use and perform a unique form of magic. This is called FoxFire, their signature talent.
Using FoxFire, Kitsune can conduct rituals, perform functional magic etc, according to their will, and so they are sufficient magic users. The FoxFire of a Kitsune corresponds to what variety of Kitsune he/she is. Foxfire of a single Kitsune can also affect other types.
Kira, being a Thunder Kitsune, wields Thunder FoxFire. She is naturally immune to electricity, she can absorb, dispell and manipulate this form of energy in whatever manner she likes.
In Galvanize, Kira unintentionally absorbed the megawatts of the electricity upon being electrocuted by serial killer William Barrow. The Nogitsune had arranged the whole ordeal so Kira's burst of Thunder FoxFire would supercharge the Nogitsune's power and possession over Stiles' body.
Kira is taught by her mother Noshiko how to utilize her Thunder Foxfire. She shows her how to use a bolt of lightning to reforge her katana in The Fox and the Wolf, and electrocuting Scott physically suppressed his heartrate, sending Scott into a vegetative state in Time of Death.
The FoxFire of a nogitsune, or a kitsune of type Void, is suited to a Nogitsune's hunger and cause for chaos and pain.
A very powerful Dark kitsune wielded a Foxfire that manifested as supernatural house flies, his animal motif. Properties of this Void Foxfire included mind control that could be inflicted upon other beings by the flies physically infiltrating the bodies of such people. Victims of this FoxFire were under the nogitsune's control similar to that of possessing a host, though to a lesser degree.
Because the nogitsune was immortal, had rescinded his humanity and no longer possessed a physical human form, his FoxFire allowed him to realize his very being as a house fly.