I just played through this game in several ways, and it has multiple endings.
The first ending I got was that the hero left and never returned to us after losing (I kept talking to him and never got angry at him).
The second ending happens if you just stand still and do nothing—he will keep moving and progressing until we eventually die by his hand (we lose control).
The third ending is where he kills us when we enter the god state (or whatever it's called), but we didn't talk enough.
The fourth ending is also where he kills us in our god state, but this time he says that we have changed during our battles with him.