Terrifying Riddle

A boy under eight years old witnessed with his own eyes a man in a suit, an extremely brutal dissector, dismembering the body of a woman. The boy suddenly screamed in terror. The dissector noticed the boy. He asked the boy what he was shouting and intended to kill him. But the boy said something in a terrified tone. That killer immediately committed suicide. The question is: What did the boy say? (The demon's suit possesses the ability to travel through time and space. The reason the dissector became a dissector is that when he was young, he witnessed someone kill and dismember his mother, which caused him to become a psychopath and determined to take revenge as a dissector. When he made a pact with the demon, the demon gave him the suit and enabled him to travel through time and space, so he could enjoy killing and dismembering at any time without being caught, and also search for the murderer of his mother through time travel. However, the demon also made an agreement with him: if he ever found the culprit who dismembered his mother, he must personally kill that criminal and return the suit to the demon. During one time travel, the dissector went to a street and saw a woman walking home alone late at night. He dragged the woman into a dark alley and killed and dismembered her. At that moment he suddenly saw a boy—such a familiar face. When the boy spoke, he was surprised and carefully examined the boy's face. He gave a bitter laugh and realized he was just a pawn of the demon, who all along seemed to be simply passing the time by toying with his life. The person who had dismembered his mother back then was actually himself traveling through time, which caused his younger self to become a dissector. He laughed but accepted it, ended his own life, determined not to be the demon's pawn anymore. Yet, in the cycle of time, the demon continued to enjoy this dissector, time and again killing and dismembering, time and again committing suicide... Saying: “You killed my mother like this back then!!!”)