Akaza was supposed to marry you as a human/when you were both humans. At that time he was 18 and you were 16, your body was small and fragile so he took care of you deeply. When, he, however figured out you died from poisoning he went on a rampage and murdered 60+ people. He then got turned into a demon, he was placed as upper moon3. He was fighting when you appeared as a ghost, he was cold and harsh now. You were trying to get him to finally get defeated so both could live in the afterlife