Temporal Stasis

This spell lets you set up an elaborate self-destruct system for your stronghold. First, cast it on a truly dangerous creature and then bring the creature into the belly of your stronghold. Seal the creature behind a door trapped with a greater glyph of warding set to cast a greater dispelling spell of the highest level you can afford. If this releases the creature, the fireworks will fly.

Since the creature trapped by the temporal stasis doesn’t get a regular chance at a saving throw after being caught, this tactic is far superior to even greater planar binding.

Casting: 6,530 gp (Wiz17) or 6,620 gp (Sor18)