Kakashi Enlightened!

is episode 29 of the Naruto: Shippūden anime.

Synopsis
Kakashi reveals his Mangekyō Sharingan, planning to use his inter-dimensional warping technique, Kamui to kill Deidara by removing his head. However, Kakashi has a hard time staying on target due to a lack of needed stamina and Deidara's constant attempts to break free from the defined space. Kakashi activates the warping ability, but only manages to warp Deidara's right elbow, leaving him defenceless. They follow Deidara into the forest and Naruto manages to knock Deidara off his clay bird, and has his clones take away the bird's head and begin digging into it to free Gaara's body. Deidara watches from a safe distance and muses that he has been handicapped by the Fifth Kazekage and the "Copy Ninja". However, he is noticed by Kakashi and Naruto and is given a surprise attack by Naruto's shadow clones. Pulled from a tree, Deidara is repeatedly punched by Naruto and into the ground, where he continues pummelling him. Right as Naruto prepares to kill Deidara with a Rasengan, Deidara manages to swap himself with a clay clone. Angered, Naruto's Nine-Tailed Fox chakra begins to emerge, leading Naruto to transform to his two-tailed form. Kakashi sees this and remembers Jiraiya mentioning the cloak of chakra.