> hit succubus with phial of holy water
The succubus shrieks and bursts into a cloud of sickly yellow smoke, which evapourates. Now you no longer have the holy water.
Oh, by the way, it turns out that I was wrong about the curse. You actually only had ten turns with which to remove the curse. Yeah, sorry about that.
Anyway, you have one more turn before the curse activates.