The 9th Class Swordmaster: Blade of Truth

Adopted by the powerful Macgovern family after the death of his entire tribe, Karyl becomes the empire's greatest swordmaster who leads his men to victory in the Oracle War. But on the final battlefield, Emperor Olivurn betrays him and dooms the nation. Determined to find the cause of this treachery, Karyl travels back in time and commits himself to learning skills he never had in order to uncover the truth. Will he succeed? Or will Olivurn's trickery outsmart him again?

(Source: Tapas)