Usually, he’s the protagonist. But maybe serves just as well as a boss.
((What am I even saying anymore, it’s like this whole thing is a game.))
In the main storyline, you would fight him once.
With the marx theme.
But in the side modes...(like dokirune)
They’re different.
Like in dokirune, his theme would change based on if you’re in a pacifist, neautral, or genocide run.