Sword Art Online: Unanswered//butterfly

Inside Sword Art Online, dying in the game means dying in reality, which turns even ordinary training into a risk that cannot be undone. Emirun and Rex, who knew each other in the real world, reunite by chance in Aincrad and join a scouting party to learn how to survive. Their group is wiped out by a mysterious player killer known only as the Black Swordsman, leaving both of them caught between grief, suspicion, and the need for revenge. Seeking the strength to strike back, they turn to Asuna for training and begin a path that may reveal the most dangerous thing in a death game is not always the monsters, but the truth players choose to believe.