Utakata's Jinchūriki Forms

Utakata was the jinchūriki of the Six-Tails. He's capable of using the Six-Tails' chakra in various and different levels, and was able to control the power up to the sixth tail. In the past, the Six-Tails has already manifested while protecting his vessel from any harm; but because of his power, he swore to never use it again.

Initial Jinchūriki Form
By using the Six-Tails' chakra, Utakata was capable of releasing its power and as such, turn the tide of battle in his favour. In contrast to Naruto, Utakata's eyes turn yellow while displaying this power, but he doesn't have any other changes like Naruto. With this, his physical power and chakra increase considerably making it possible for him to free himself from any control such as Shiranami's Character Bind Technique. In this form, he displays waves of chakra towards many enemies and is capable of overwhelming them without any problems.

Version 1
By releasing more of the Six-Tails' chakra, Utakata can create a chakra cloak. With it, he can suppress powerful kinjutsu, as done with Hotaru, with no harm to her or to himself.

Version 2
Whilst resurrected, Utakata displayed the ability to enter a "Version 2" form, by moulding the Six-Tails' chakra into a human-like shape around himself. When entering into this form, the sudden increase in chakra was such that it instantly vaporised Killer B's ink clone, which had immobilised him at the time.

In addition to forming a dark chakra cloak around his entire body, his appearance becomes more rounded, like that of the Six-Tails. With the power granted by this form, Utakata not only manifests all of his beast's six tails, but also becomes able to ooze a highly corrosive, alkaline substance that seemingly makes it more difficult to trap or compress him.

Partial Transformation
While it is unknown how much control Utakata has over the Six-Tails, after his resurrection, he was able to form one of the beasts tails without the use of a chakra cloak.

Full Six-Tails Form
During the attempted forced extraction by his master of the Six-Tails from Utakata's body, Utakata slipped into his full Six-Tails form and killed his master. After this incident, Utakata defected from Kirigakure and developed his hatred for master and student relationships. It is not known, however, if Utakata was in control of his body during the transformation, or if the Six-Tails took control, similar to the Nine-Tailed Demon Fox when it takes over Naruto. When Utakata tried to stop Hotaru's kinjutsu, he asks the Six-Tails to give him the power to stop it and as seen in the end, the Six-Tails didn't take control of Utakata.