Grave yeard on scarlet island. You must kill thoms thorkve. Hes location is random. Mostly underground of montero or elon.

Or use the scan savegame mod and find where you can get a resurrection scroll.

I guess I were lucky. Found it under the caves in montero. I sneaked by a cyclop hero wich was invincible and under there a resurrection scroll were laying on the floor.

Besides, I dont need to use it atm. I've had 20 fights in a row with no losses.
Troops using atm, 6 giants, 49 paladins, 2 groups with 75 in each repairingdroids and 100 of the other droids.
Simply using the resurection ability on the paladin if any died along with healingspell and repair on the droids;)

Yep ress lost its power in AP, you barely need unless you play demon army