This is episode 53 of 62 of The Janitor Swordsman. Play it below, then continue straight into the next episode — the whole season is free and needs no account.
The closing stretch of the season, where the arc pays off.
In a world where fencing settles disputes, the Sword King Michael dies fighting the Seven Kingdoms. His brother David, who vowed never to wield a sword, breaks his oath to save Emily and Sword Hall. He sacrifices his hand, defeats the Sword Demon with his left, and restores the nation's honor.