What narrative substitutes remain?

Well, you've got three rounds, plus one combat round before the fireball goes off (at the end of official Round 1). So do what you can.

Mark, so what did Vrill accomplish? What have the PCs accomplished, for that matter?

He was 4th level when you guys were 1st, he was 8th level when you guys were 5th, now he's 11th level when you guys are 7th. So he's gained some more xp. But remember, there are between four and eight of you and one of him. Again, just fighting a single 8th level magic-user here would be a boring fight, it'd already be over. He might as well win initiative and magic missile himself to cheat you from a final victory.

This whole recurring villain thing is a major trope of the genre, hence the parody of such here. Most of the ways involving recurrance involve things you'd call cheesy. So if you think it's bullshit, honestly I'm wondering what other tropes or narrative structure you'd use, or have used, in your own games?