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
But, although Hao Baiyun and Gu Xingfeng – who Yi Bing are grateful to not meet in this world again, are Twin Souls of Fate, their situation is slightly different from Yi Bing and Huo Ling. Hao Baiyun and Gu Xingfeng are where one suffers, the other will also suffer. And if one meets a good fortune, the other will also be fortunate. Theirs is a win-win, but also lose-lose situation. Yi Bing doesn't know whether to feel relieved or envy them.
Of course, Shen Sheng, although disclosed this secret to him, but Yi Bing knows Sheng Sheng also hides more secret. The secrets Sheng Sheng would disclose are only those which he finds not useful or won't affect him even the slightest. Of course, he would also disclose these secrets in order to spite the Heaven.