Inspired by Teal_Blue's signature: Phat Loot. Hlidskjalf, Singasteinn, and Pandora's Box each spawn - directly outside a bandit keep. (Thankfully, this version of Pandora's Box doesn't accelerate the next woe countdown.)
Devices of Daedalus. Half of all bandit infantry and archers gain flying via the wings of Icarus, and all bandit siege engines gain a large boost in power.
Phobos rides! All humans are fear-stricken, and will retreat towards the nearest friendly town, refusing to leave a small radius around the town for the duration of the Woe.
Naglfar nears completion. For every human unit that dies, its fingernails and toenails are added to the fell ship. If too many mortals die while the Woe is active (five turns, or so?), Naglfar will be completed and will deposit its cargo of frost giants on the land.
Apple of Discord. The Apple appears at a random spot on the map. All of the gods will move towards it and fight over it, killing everything near it including each other, until only one is left. Thanks a lot, Eris.
(having only played a tiny bit of the game, I can't say for sure that none of these concepts are already included anywhere)
