There is a scenario idea here too!
Somewhere in the frozen city is a giant chess board where the pieces are Contstructs or Demons bound to the confines of the playing area. Opposing warbands can substitute themselves for playing pieces and then engage in a game of chess with a difference. The pieces would move like chess pieces but the Wizards/Apprentices/Soldiers would move a number of squares equal to their movement. One action per side per turn. If you move onto an opposition piece/soldier then you fight consecutive rounds of combat until one piece/soldier is destroyed. Each time a piece is destroyed a treasure token replaces it (and is automatically picked up) to get your treasure to a place of safety, you have to get it off the board at your opponents end, a bit like replacing your queen.