They might be, or at least the day after. Jack's father was taken to the gods to get the sword forged and went to fight Aku straight after, and defeated him. Then we see Jack as a baby, so yeah, that's kinda cool. Though Aku didn't have a conscious for many, many years until the arrow Jack's father had gave him that, but he was still a being of evil ever since the era of dinosaurs. He was more of a natural disaster then.