Six Paths Senjutsu

The Six Paths Sage Technique is an empowered state, similar to Sage Mode, which drastically empowers all of the user's abilities to a far greater extent by apparently combining senjutsu and the chakra of either the Ten-Tails or of all nine tailed beasts.

Madara's Version
Madara has stated that he possesses this technique. Whether this is purely from becoming the jinchūriki of the Ten-Tails, or a result of him having previously absorbed Hashirama Senju's senjutsu chakra is unknown.

Naruto's Version
While using this power, Naruto takes on a similar appearance to his Nine-Tails chakra-enhanced Sage Mode, while lacking the pigmentation around his eyes that a normal Sage Mode would entail. In this state Naruto somehow managed to rekindle Might Guy's extinguishing chakra after the latter had used the Eight Gates Released Formation, as well as restore Kakashi's original left eye after Madara stole his Sharingan. Naruto's physical abilities were also bolstered to the point where he was able to overwhelm Madara in his Ten-Tails jinchūriki form, forcing him to absorb the entirety of the Shinju.

Naruto can extend the capabilities of the form by further drawing on the chakra of the nine tailed beasts, causing him to don a chakra cloak which is noticeably more powerful than the Nine-Tails Chakra Mode. In this mode, the chakra forms into a light-coloured coat with a dark-coloured bodysuit underneath. The "bodysuit" covers his torso, reaches down his arms to the knuckles, and down his legs, stopping just above his sandals. It has a light colored circle where his seal was placed as well as magatama markings around his collar. The coat has the typical markings of the Six Paths Sage Technique; a Rinnegan above nine magatama, on its back. In this state, Naruto is able to manifest the Truth-Seeking Balls, wielding two of them as short staffs. His speed is immensely increased as well to the point in which he can match Sasuke's instant teleportation with sheer speed.

Obito's Version
Obito achieved two forms of the Six Paths Sage Technique; the first which he achieved in his initial form. In that his body became scaly, he got the Rinnegan symbol and the nine tomoe on his back, and he possessed only two Truth-Seeking Ball which were attached to his hands. In his controlled form, he possessed a chakra cloak behind him, gained small horns on his head with one over his Rinnegan being bigger than the one over his Sharingan and his Truth-Seeking Balls increased to ten.