Cain has a secret that he’s kept for a long time. He’s immortal. He’s the one from the story that killed his brother Abel. As punishment God made him immortal, and now he’s lived many places throughout the ages. All to end up as an investor in the upcoming VRMMO called Sword Art Online. After hearing of its turn into a game that kills its players if they die, he takes out the NervGear and copy of SAO he received due to being a high paying investor. He dives into this world to see if this is finally the thing that will be able to kill him and release him. That doesn’t happen though, and now Cain must live inside the world of SAO with all the other trapped players.