Liam: Offending one of his guests (Nadhew included) so badly that they'll never speak to him again.
Addle: Waking up with a hangover and not remembering anything from the night before. Or, worse yet, remembering everything.
Solude: I dunno... Falling asleep while kneeling in the throne room?
Tim: Doing something - anything - that might get him told off. Like dropping a teacup. Or breathing.
Nadhew: Finding out he needs Viagra. And having Loki discover a packet of it in his mail.
Sittra: The first wrinkle. The first grey hair. The first open pore. Cellulite. Watching a baseball game with Nadhew.
Claydle: Being confined in one of those cells where the light is on 24 hours a day. Or being forced to watch episodes of the Teletubbies, the Care Bears and Barney. Then again, such monstrous torture might appeal to him.
Loki: Having to stay in Flaithis until he's learned some manners. (Or was that the worst fear of the collective population of Flaithis?)
Lugh: Running out of starch and metal polish.
Cifer: A very large magnet.
Elves: A bulldozer. (Emel's personal nightmare: Agent Orange.)