Sodeumaseuteoui Hwansaeng

Despite his ordinary skills, Sir Shake, captain of the guard, dedicates his life to defeating the demons and bringing about an era of peace with the immortal swordmasters. However, when Shake finally succeeds and also becomes a swordmaster, he dies, only to reincarnate 20 years later as Asher. He's shocked to find that his comrades have vanished and demons are rumored to have returned. In the midst of all this chaos, can Asher find his former allies and vanquish the enemy for good?

(Source: Tapas)