俺が信じていた仲間は全員、悪徳勇者に送り込まれた刺客だった

The Hero of darkness Shion was suffering mentally while being at the position of the strongest on the land. It was his companions who completely saved him when he became distrustful towards other people. Although Shion decided to trust people again because of the girls――a tragedy occurred just then. There was a cruel betrayal from those companions he believed the most in the world. Shion barely escaped with his life, but he had come to lose ninety percent of his strength. And then above all, he received serious damage to his heart. Shion gave up living and wandered in a forest to try dying, and then one monster appeared in front of him. “Will you not kill me?” The monster made the request to Shion, who was strong even when having lost strength, to kill it. However the action that the not yet dead Shion took is——