Megami no Daikousha to Natta Shounen, Banjou no Ou to Naru

Luca, whose homeland was destroyed by a powerful curse, ended up bearing the curse himself. Determined not to let anyone else suffer the same misfortune, he sets out to uncover the curse's true nature by becoming a top-tier adventurer. Along the way, he meets the goddess Selimys and decides to become her "Proxy" (follower). Thus begins an adventure fantasy where a boy, now a servant of the goddess, races through a world entangled in divine conspiracies alongside his comrades!

(Source: Futabasha, translated)