Kono Hi, "Itsuwari no Yuusha" de Aru Ore wa "Shin no Yuusha" de Aru Kare wo Party kara Tsuihou shita

A Demon Lord has arisen, and the world awaits a hero. In a peaceful village, two young boys—Foyle Austin and his best friend Yu—have long dreamed about being heroes, but the legends say there can only be one. Their paths forward seem decided when the goddess declares Foyle a "Hero," while leaving Yu's destiny unclear. But Foyle has a secret only he knows. The role given to him by the goddess is actually "Fake Hero." Far from being destined to overthrow the Demon Lord, defeat awaits him at the true hero's hand, and Foyle has a good idea who that will be. When Foyle expels Yu from his party, he cements his role as the true hero's adversary. His powers begin to fade as his friend grows ever stronger. Foyle clearly won't be the one to save the world, but after an encounter with a mysterious elf in need of help, he sets out to prove that even the villain can be a hero to someone. (Source: J-Novel Club)