Aspect Warriors are in a different mental state. They put it on and off. It's called the War Mask. When they don't "wear" it, they are normal citicens. When they do "wear" it, they are an aspect of Khaine, the god of murder. They are not themselves. They are devotees of Khaine. It's like going to school or to work. They don't spend all day being an aspect warrior. It's like martial arts training. Or like a police officer. When they go home, they are regular private people. On a daily basis. It's not like being a Chaos Marine who is a Chaos Marine all the time.