Stolen by the Demon Lord, but Was I?

Your entire class is summoned to another world by a goddess to become heroes. When the light fades, Mephesto alone awakens inside the Demon King's castle. Secluded, brilliant, and drawn to the idea of becoming something greater, he is chosen by the goddess's enemy instead of blessed by her. Granted overwhelming power as the Demon King's Apostle and the unique skill Dark Matter Manipulation, Mephesto becomes stronger than the heroes he once called classmates and must decide whether he was truly stolen at all.