Kyuuki

Kyuuki (キュウキ, Kyuuki) is the spirit of a tiger and the guardian ghost of Tao Ching

About
Although called Kyuuki, it actually has no real name, and so was instead named after Kyuuki the evil tiger god of the Shikyou Legend, because of their similiar appearences.

O.S. Kyuuki
O.S. "Kyuuki" (キュウキ)

Description: Ching's spirit looks like Kyuuki (the evil tiger spirit from the Shikyou legend) so he named him Kyuuki. The medium is Tao Ching's Chinese Beretta which has the image of Emperor Shun, the one who is said to have defeated the four evil gods in the legend, engraved on it. Kyuuki is shot from the gun like a bullet and attacks the enemy just as quickly, much like the Archangel spirits of the X-Laws. It is possible that this is the technique Ching used to kill Lee Pailong.
 * Shaman: Tao Ching
 * O.S. Type: Spirit Type
 * Spirit Ally: Kyuuki (animal spirit)
 * Medium used: Chinese Beretta

Anime/Manga Difference
Kyuuji never appears in the anime, even though Tao Ching does.