Monologue through a stone of farspeech or a ward-tripped illusion spell. Hell, have the villain's illusion disintegrate only for it to trip 18 other wards that all seamlessly continue the monologue in a deafening cacophany of voices, like the BBEG knows alllll the tricks. I feel like a good DM can get creative on the spot, even if it trips them up a bit.