Bloodthirstiness… A desire to kill someone… These strange notions—at least for some—have always haunted people. And even if you strip them of all technologies, possibilities, and knowledge, they will still search for a way to kill and maim. At best—only to wound. But they never refuse the chance to spill someone else’s blood. Even the knowledge of countless bloody wars in the past never stops them. It’s as if the memory of such horrors just erases itself… A powerful and extremely cruel one. Someone who conducts a terrible experiment over Humankind.