Corruption didn't hurt much but the last turn I lost a big fight for Utgard capital and lost almost everything I had there (Utgard lost everything but damn immortal mummy that never runs). I lost some unique items and a handful of mages but that was like a drop in the sea actually. A FoTA caster died there as well so I was lucky that your AC dispelled FoTA))
One of the main reasons why I lost was that my equipped fairy queen who should have casted Mass regen and Fog warriors died from a horror as she was already horrormarked. My main wish-empowered Chtugul who kept Strands of Arcane Power was scripted to also attacked but was scripted to Returning. No more attacks happened. Probably, clam forgers who use 5-1 gems for a clam didn't seem to be good enough targets for horrors
I planned to restore FoTA this turn with elemental king (I was thinking hard how to protect him from horror), to kill Mother Oak caster and next turn to raise either Purgatory or Wrath of God depending on who would seem bigger danger. Also I planned to cast 300-350 gems Dispel. I hope, it would have been enough for your AC.