Back in the Nightmare Realm, Sheyan had discovered a few new contact type infectious disease skill trees. The ultimate abilities of the skill trees included the Ebola hemorrhagic fever, Tetanus and AIDS.
After that, he had gone back to the real world. At that time, no one knew where he went specifically or which choice he made; they only knew that he had returned to the real world to learn a new disease. Sheyan had claimed this disease to be his ultimate hidden card, so he would not disclose what it was before he used it.
Of course, many people had speculated that it must be the Ebola hemorrhagic fever, because AIDS' reputation was simply too notorious; Sheyan might be strong, but he probably would not dare to infect himself with this disease.
There was a saying that a man should be harsh on himself. It appeared that Sheyan agreed with this saying and had put it into practice. He actually climbed the skill tree in one go until he got to the final disease!
AIDS!
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