Housed an army in one spell.
So I've got a game humming along, as you do. And my sphere of influence (or Zone of Control?) accidentally rubs up against this wizard guy hanging out in his keep. When it said "Deadly Epic Fire and Death Will Befall You" when I looked at him up first seeing him, I decided to go the other way (naturally).
So anyway, my ZoC being over his keep apparently made him mad or something. So he walked up to the nearby city, stepped forward, cast a spell which I have no idea what was, and promptly obliterated the entire army guarding the town. Did seventy or eighty damage in something like an 8x8 area of effect.
Aaaaaaaaaaaaaaaaaand I promptly quit the game. That guy could destroy my entire civilization. Easily. Actually, he was well on his way to destroying my entire civilization. In fact, he could probably destroy every civilization. Probably all at once.
Whiskey Tango Foxtrot.
And so a game that was really fun is suddenly not fun.