Naruto: the God of Death at Full Level, She Just Wants to Pick up Cubs

[Time travel + development system + heroine + OOC warning] She is the God of Killing "Yao" with a 100% completion rate in the underground world. She sweeps across the three realms with one knife and no one dares to tell her her true name. After reincarnation, she became a six-year-old mute girl at the bottom of Konoha - her soul was broken into seven pieces, she had no emotions, no will, and the only thing she could say was one word: "Brother." Her brother Uzumaki Naruto, six years old, ate expired rice balls and was stoned by the whole village. He used his arm to block the broken glass for her and said with a smile, "Don't be afraid, sister." She won't be afraid - she won't feel anything. But before the stone fell, her hand grabbed the corner of his clothes. The Five Great Nations thought she was just a useless jinchuriki. Until the code name "Yao" reappeared in the world and cleared the Chunin Exam in three minutes; until the villain orphans she picked up formed three ace teams; until the sixth country emerged out of thin air on the border between the two countries, with the country's name "Moon" and the first article of the national law - never abandon any family member. Her soul is still broken. Each time she retrieved a piece, she gained an extra layer of human emotion. And the last piece of "love" was hidden deep in the soul of the boy who had been standing in front of her since he was six years old. To get it back, their souls must be completely fused.