Battlefield spell + retreating?

[Xietor]

Yes.

Otherwise, there would have to be a statement before the game started that a high level air spell was banned. What I did in Kingmaker was use a clever Mod written by Twan that made the spell have a fixed duration.

Absent the mod, I did not want to ban Mists of deception completely. But the mod is the perfect answer. Keeps the powerful air spell in the game, and removes the exploit completely.