The Story of Bihyung: Enchanted Master of the Goblin (2025) : 1x9

Bihyung falls into a deep coma, and without the spiritual energy of his master, he may never awaken. Yet his master had vanished a thousand years ago. Samsin pleads with Geumbok to travel back in time to find that person. As Samsin performs the ritual, Geumbok lies beside Bihyung and slowly drifts into sleep. When he opens his eyes, he finds himself in an old, decaying house of the past—only to face Bihyung holding a dagger to his throat, mistaking him for a spy sent by the enemy.