I Am the Golden Cudgel, and My Former Master's Surname Was Ox

I am the Ruyi Jingu Bang (Golden Cudgel). My current master is the Victorious Fighting Buddha, Sun Wukong. But I have a secret. Before I became the Ruyi Jingu Bang, I had another name: the Iron Cudgel. My former master was the Great Sage Equaling Heaven, the Bull Demon King. At the Flaming Mountain, we clashed. He looked at me, his eyes not filled with anger, but with sorrow. "In the end, you have become someone else's weapon." At that moment, I felt my staff tremble. Not because of the battle, but because I remembered a forgotten memory: five hundred years ago, Sun Wukong "borrowed" me from the Bull Demon King.