In his lifetime, Shirou walked the path of suffering and despair. He and his comrades fought for their faith and beliefs, and in return, they failed and died. He once hated everything, from God to humans. He claims that he hated humans, not because they had killed him or his comrades, but how humanity easily accepted it as a repeating system in history where life is priceless yet has no value. He finds humanity to be just like Ouroborus, eating themselves in order to grow. Shirou admitted to his failure, his mortality and his guilt. So, he forsook his heart filled with hatred, for the sake of humankind's salvation. He claims he does not hate humanity anymore, and that he will save the current six billion people and the people from past and future. In reality he is trying to save humanity to forgive himself for not being able to save a single person,he wishes for everyone to throw away their selfishness and create a world where everyone is saved and happy. He desires to make use of the Holy Grail to fulfill his own ambition. He simply wished the happiness of all mankind, for innate goodness to be found in the heart of all humanity and the annihilation of Angra Mainyu: All the Evils of the World.