Magic Scale

[PrinzMegaherz]

So, Ulm's troops would actually tend to be fighting summoned creatures that were even nastier than usual, wouldn't you think?

But that has nothing to do with the generell idea. Besides, there would be certain ways to counter it: Building castles at the border, and Attacking the enemy forces after they entered your dominion.

Another proposal: Drain works like diseased. As long as the summon stays inside the drain territory, it will loose HP and might get afflictions (because its dissolving).