Quote Originally Posted by Face Of Evil View Post
You could have the Balor or some other suitably strong creature stomp the DMPC flat with one hit. It takes exactly one line of dialogue, and there's no better way to announce "THIS IS A BOSS FIGHT!"
I am Aslan Cross and I approve of this post. I've done this before. The DMPC was actually a PC on her way out due to the player quitting.