Previously, Hero had attended as a spectator to a tournament of immortal creatures fighting to the death. After seeing their inability to control their own actions, Hero tried to take control over them himself. After successfully escaping with one immortal animal, Hero quickly trained it to live on its own and set it free.
This episode - Hero is training. He is just about to learn a new move and it requires great skill and focus. While focusing, he goes off the topic he was focusing and notices something strange. Strange messages, unknown from whom, were coming to him. He couldn't understand most of them, but he got something about his greatest enemy. After this confusing message, he saw a vision in his head. He had seen this before. It was in his dreams, and he had not like those particular dreams. It had something to do with his child hood and he did not want to be reminded of it. Even if he wanted to, it was impossible because he had not remember anything from it.
He tries to continuously throw away the horrible image in his head but it won't go away, no matter how hard he tries.