I had a player banish Rary the Traitor.

In our game he had done a 9/11 on the Circle of Eight and the players had already rescued Tenser's clone from the moon. Based on the spells that had his name on them I imagined that he wasn't just a Diviner, he was The Diviner.

They had come by some McGuffin, I forget which, and did a Message to an ally. Rary himself wanted it, because when you're the Diviner you get tools like that, so he showed up looking like that ally and I played the scene a little off. Party's own diviner clocked that something was up, tried a Dispel Magic and then it was on.

He went for Banishment and had 60 seconds to tell the party exactly why they were fucked and magically get word out to every friend they ever had, that was a beautiful minute.