"Aesthetics of an Artist" (芸術家の美学, Geijutsuka no Bigaku) is episode 280 of the Naruto: Shippūden anime.
As the Allied Shinobi Forces' headquarters scramble to deal with White Zetsu Army clones infiltration issue, word reaches the Fifth Division of the development and Mifune instructs his division accordingly. Kurotsuchi travels to the Fifth Division to speak to Deidara and interrupts him being freed by a disguised White Zetsu clone. As their conversation goes nowhere, she requests that Kankurō opens Kuroari so she could speak to Deidara directly. Before this could be done, however, Okisuke arrives and interrogates the samurai on guard who responds incorrectly and is cut down mercilessly. Deidara, however, is able to use a sword as a makeshift ground rod to channel the electricity from his body and escape. As he and several White Zetsu flee, Deidara notes that he needed to get his hands on some Explosive Clay. As they escape White Zetsu clones continue to dwindle until Kabuto Yakushi sends Chūkichi to aid them. Finally reaching a small amount of clay Deidara is able to fight and later self-destruct using the sword once again as a ground rod when a Konoha-nin from the Communications Team tries to incapacitate him with lightning. Shocked to see himself reforming, once the Summoning: Impure World Reincarnation is explained to him Deidara concludes that his art and the technique were incompatible since his art was supposed to be for a solitary moment and not immortal like Sasori. Eventually, Deidara is recaptured within Kuroari after falling prey to Kurotsuchi's Sasuke Uchihatransformation, Mifune's clever use of a battery to imitate the effects of Lightning Release and being lured to an area where he could not use the sword to siphon off the charge. While trapped inside the Kuroari once again, Deidara states that he has found his super ultimate art and looks up at the moon.
Okisuke noted that the correct response to his statement "mountain" was "river". This may be an allusion to either the show "'The Burning Mountain River", which famous samurai and Mifune's namesake Toshiro Mifune appeared, or to the Japanese saying which roughly translates to, "the country is in ruins, and there are still mountains and rivers".