Out: the Past of the Five Immortals in the Northeast

Before my grandfather died, he gave me a wooden box and said, "Open it again after I close my eyes." When he opened it, he saw a rusty sword with three words engraved on it: Immortal Sealing Sword. That night, grandpa's coffin was knocked open from the inside by something. Lying in the coffin was not Grandpa, but an old yellow man wearing a shroud. The old man in the village said: It is your responsibility to pay back the debts your grandfather has owed in his life.