Easygoing Territory Defense by the Optimistic Lord

Reborn as a marquis' fourth son, Van was once hailed as a genius prodigy-until he's exiled to a nameless frontier village for possessing Production Magic, a useless type of magic in this world. But when he uses his "useless" power to craft weapons, tools, and wonders beyond imagination, the village begins to thrive! What began as exile is now the start of a new life-and a world-changing adventure!