The Helmet Splitter: Jinin Akebino!

is episode 284 of the Naruto: Shippūden anime.

Summary
With no sign of the enemy, a wary Kakashi Hatake tells the Third Division to rest up while they can while maintaining a half-hour guard shift. Headquarters sends a giant scroll and carrier to the division which Kakashi gives to Sai in order to use the fūinjutsu taught to him by Danzō Shimura. Rock Lee is assigned as Sai's bodyguard as he would be rendered unable to defend himself while he used the technique. Sai, however, is still apprehensive about using the technique as it required him to use "emotional energy" to make it more powerful and as an ANBU from Root, they were taught to suppress such things. He was also concerned by the fact that when he attempted to use this technique, there lied the potential for him to be consumed by negative emotions. As dawn broke the next day, the division is set upon by Gari, Pakura, Jinpachi Munashi, Kushimaru Kuriarare, Ameyuri Ringo, and Jinin Akebino — all of whom take to guerilla tactics to divide the division's forces and take them down individually, and upon realising this, Kakashi sends word to his division to stay together. Confronting Jinin who was slaughtering his forces, while Sai and Ensui Nara stood by to aid in the sealing, Sai is still initially unable to use the technique. Almost completely overwhelmed by memories, Sai finally realises that emotions and even negative feelings were not always detrimental, and is finally able to use the Sealing Technique: Tiger Vision Staring Bullet to seal away Jinin. With Jinin sealed, the other reincarnated shinobi retreat and they are ordered not to pursue them individually.

Credits
¡Kabutowari! Akebino Jinin