Tatsuki Fujimoto 17-26: Nayuta of the Prophecy

Kenji's little sister, Nayuta, has horns on her head, cannot speak properly, kills animals, eats their carcasses, and is generally abhorred by everyone. After all, she is prophesied to destroy the world. However, she is his only family and he vows to do his best to protect her. He has been managing well until Nayuta incurs the people's wrath with her actions.