The large Elementals that rule the the special locations (like the frozen lands) are extremely vulnerable to mass debuff spells.

1 Mass curse and 1 Wither were inflicted multiple time each. Resulting in among other things, a negative spell resistence.

Single target spells only had a single effect (the on the make all hit critical) and I believe the mass version hit 9 times, so I makes me think the mass versions are applying their effects to each occupied square. The Ice Giant (V...whatever) takes up 9 Squares, and got cursed and withered 9 times.