50,000 years ago, Hell was destroyed because of too much Foul from the resentment of the souls that later turned to Soul Eaters and devoured everything in their wake, leaving nothing of Hell. The gods above in Heaven, in order to take care of the newly-died souls, created the Afterlife Department comprised of grim reapers. Huo Ling was delivering food that day when he met Yi Bing and the guy gave him a warning. When he arrived to the customer's unit, he was killed. Huo Ling: you set up a death flag for me! Yi Bing: I'm a grim reaper. I'm the flag myself. Let me help you solve the mystery of your death. Huo Ling: your sister! Alternative title: The Different Ways I Died at 23 Update: daily
"So, yao are demons that are of any form, most of the time representing evil?" Huo Ling said after the man explained to him about the mermaid earlier. "Ghosts are also a yao, but we aren't evil…" he muttered.
"Yao is a general term. In this world, there're only the humans and yao." Yi Bing said as he looked at Huo Ling who's contemplating his words. "Demons aren't necessarily evil. Evilness are from one's thoughts, not their heart. Since our heart is our soul." he said. "Only one's mind can affect – taint their heart, thus tainting their soul after." He explained.
"So, as long one has a clear conscience…." Huo Ling said.
"They won't turn evil." Yi Bing said. "Yao is just a classification." He told Huo Ling.