everything does have a counter, you can tell by moving your mouse over the target.
it will tell you how many kills, this is very useful when selecting a specific spell or unit to attack a single target.

after 30 mins of fighting the demons to free the son of the king dwarf, i managed to pull off a victory with all my units wiped out but lucky with necro skill, i got 5 evil beholders after the battle! this is truly an awesome epic game !!

Haha, I didn`t mean a counterATTACK, if that`s what you are trying to say. IF it`s not, then I challenge your definition of counter

Tne only counter for demon units is mass magic shackless