Special Powers!! (特別な力!!, Tokubetsuna Chikara!!) is chapter 231 of the Naruto manga.
Seeing the demon fox cloak, Sasuke finally understands why others find Naruto so interesting. Naruto lunges at him and, although Sasuke's Sharingan is able to predict Naruto's movements, it cannot predict the cloak's actions. Sasuke tries to attack from a distance but the cloak not only protects Naruto, it also extends his physical range. Discovering that he is no match, Sasuke advances his cursed seal to its second level to prove his abilities superior.