He sacrificed himself for his people in the war and was shattered because the blade that was attached to him was broken. Onikiri restored everything he carried - his life, his arm, and his blade. That broken blade was reforged by Minamoto no Yorimitsu and molded into the look of a young boy. The newly born Onikiri chose to face up to the past and become the sharpest and the most tenacious weapon. Hates Yorimitsu. Short tempered. Curses Alot.