Sasuke used "Kirin" as his final jutsu to beat Itachi, in Naruto manga chapter 391 . It seemed like this jutsu was Sasuke’s trump card in the battle of beating his own brother.

What exactly is "Kirin" ?

Shinobi who can perform Katon no jutsu , usually use their chakra to manipulate the nature and to create fire for fighting in battle. The same goes for other elements; Daton no jutsu , Suiton no jutsu , Mokuton no jutsu , so on so forth. The amount of chakra that a human can produce is limited, of course.

Unless you are a vessel of a Kyuubi like Naruto, who could create massive numbers of kage bunshin (not just the usual bunshin), no one, no shinobi can exceed or even come close to what the nature can produce itself. Of course, even Naruto plus Kyuubi could not exceed the mother nature itself.

And "Kirin" uses this advantage. The advantage of mother nature itself. Sasuke initially created a cumulonimbus cloud for thunderstorms. And instead of using his own chakra for performing "Kirin", Sasuke channels an enermous surge from the sky, to create Lightning Element Technique . And guide it to his opponent, which then was Itachi.

Now, this is something worthwhile in this chapter. And the fact that even with that much power channeled towards Itachi, he still could endure it and save "his own" final jutsu for Sasuke, this is what the battle should be, from the start.

Kirin strikes

( Read Naruto manga Chapter 391 here ! )