Quote Originally Posted by MonkeySage View Post
Now, in the big bad's eyes, the players are more of an annoyance; dangerous only because of what they know, not what they can do. Being a patient and deceptively smart villain, he's biding his time until he can claim that he was provoked. Once that happens, there's no power on the planet that could save them from his wrath.

This villain has managed to ascend the ranks of chivalry until he reached the very top; when his father died, he was named heir to the imperial throne. His sword is as sharp as ever. He has a reputation for his nigh-supernatural strength and speed.

The difference between overall party level and his challenge rating, by himself, already spells TPK. And he's accompanied by his knights, the 5 greatest knights of the realm.
Show how insignificant the party is to him at this point. You could set up the conflict so that he can only be attacked in a place where he can easily escape. Have him step out of the room and leave only one of his knights to deal with the party. Show the party that it would only take one of his guards to kill them, and that the Big Bad doesn't even see them as a threat.