how do i deal with Arch Demons doing 'half'?

[poodle]

they usually have first attack too. but i hate running into these guys since they seem to randomly take half the units, and sometimes from my favorite troops.

[DGDobrev]

They only take half of them if the archies' leadership is more than the leadership of your stack.

If you can't do that, try restructuring your army's positions. That helps sometimes. If not... well, coming back to kill them after you've gained some more leadership is the way.

[KongMysen]

Or you you can "solve" the halving by casting Time Back. Excorsism and pain mirror works great too.
If you don't have timeback and your troops are smaller than the enemy Arch Demon, follow DGDobrev's advise and return later.

In combat just focus fire on them the first few rounds and they won't cause the same threat once their numbers have been downed to lower leadership than your own troops

[Harush]

It's funny, when fighting Arch Demons, I usually am hoping that they will "half" me on the first attack, so my mage can hit them with 2 pain mirrors in a row, usually enough to take out even a big stack of demons. Then I time back next round and am good as new.

[dashcunning]

If you can manage enough initiative to attack first, a well placed trap is sometimes helpful. Gives you a full turn to lower their leadership.