Eight-Tails Chakra Mode

 like other transformations like it, is an advanced and heightened transformation unique to those who have the Eight-Tails' chakra (Sealed inside them, in the similar manner to that of Naruto's) along with acquiring perfect control over it. As the current jinchūriki of Gyūki Kūkan Mugetsu can essentially utilize this mode.

Appearance
When this mode is activated, Kūkan gains a chakra shroud with Eight unique magatama's on his back. The large Magatama being placed at the center and other seven revolving around it. His hair becomes spikier than before and strangely resembles Gyūki's horns. Kūkan also grows two small spikes from his shoulder, the colour of his eyes changes from onyx to crimson.

Attributes
Like other jinchūriki transformations, this form grants Kūkan tremendous boosts of speed, strength, durability, stamina and defenses. With his strength increased to such levels that he could easily life a Tailed Beast Ball with a single hand (while applying minimum effort). He was also able to take down several shinobi's at once with his increased strength, within a flash with his increased speed. Some stated that his increased speed was so immense that even skilled Shinobi's had a hard time noticing his movements. With his increased durability, he was able to directly take hits from a skilled Lava Release user and a Storm Release user at the same time. He also retains his ability to utilize the Chakra arms and the [[tailed beast s