DISCLAIMER: I don't own Naruto. I just made up the jutsu for one of my OCs. Because I'm lame like that.
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The Berserker Jutsu
The Berserker Jutsu is a bloodline jutsu that runs through the Akane clan. However, unlike other bloodline jutsus, the Berserker Jutsu can be copied by the sharingan. There are some risks to copying the jutsu, including that it can be life threatening to both you and your team-mates.
The Berserker Jutsu takes place over three stages. In each state, the user loses more and more self-control, as well as the ability to differentiate between his or her allies and his or her enemies.
In the first stage, the user still has most of their self-control. Chakra begins to build up and gathers in the legs (for speed), the jaw muscles (for biting strength), and the ears (for hearing). The user's pupils are beginning to shrink, at this stage they are about half the size they are normally. They can still tell the difference between friend and foe.
When the user passes into the second stage, they are losing self-control rapidly. The chakra building up has almost hit max capacity, and the user is gaining speed and biting-strength, and their sense of hearing is almost so good they could hear someone in the bushes a mile away. They are still just barely able to decide who their ally is and who their opponent is.
Finally, the user hits the third stage. They have no self control, and the chakra has hit max capacity. They have breakneck speed, biting strength equal to that of a hyena (they are able to break even the hardest bones in the body), and they could hear someone break a twig a mile and a half away. The user is no longer able to tell the difference between their friends and their enemies.
They will kill on sight.