Evil gandalf

I was playing lord of the rings return of the kings and I put it into my classic sony GameCube and thats when I saw something was wrong the title was in all red and there was gandalf with blood for eyes and black outfit I decided to play anyway I noticed something strange when I started playing and it was that I was playing as gandalf instead of frodo and he was the same as the title screen as soon as I beat sauron gandalf disappear and then he was behind me I scream and jump out of my room but he catches me no one saw the boy since then