What is your nastiest surprise ever in Dom III?

[Strages Sanctus]

massed mages with no script casting phoenix pyre on themselves and setting off an army destroying chain reaction... not once but twice. Two big armies and dozens of mages

[Gilded]

Summoning otherworldly beasties of the void with middle age R'lyeh using a Void Lord pretender god only to have him get feebleminded when summoning a single lesser otherness. You'd think that a powerful void being itself could sustain a little bit of unimaginable horror but guess not. :|