This fight seems pretty easy for a mage atleast. Though i plow through even impossible armies now with mine, only thing that can be annoying are dragons (especially black) due to magic resistance. Though I have a workaround for black dragons now
Lay down a Trap (4000-6000 dmg) and use Emerald Green Dragons to drag them on to the trap, while thing usually kills 6 or so. Tactics help with positioning your troops so they hit a hard target on their first strike.
Did Karador at 23-24, estimate i had around 13k leadership worth of troops.
8 atk, 20 def, 37 int (ish)
Dwarven Cannoneers (+100% atk, +30% crit chance and + 1 morale from the set).
Royal Snakes (+100% atk from wife, + 3 dmg from Ring of the Snake king).
Emerald Green Dragons (had
.
Cyclops (had 9).
Inquisitors (don't have ressurection, but inquisitors + Gift is a nice substitute).
Lost 9 Royal Snakes in total. Just blasted the everloving crap out of his army with rain of fire, and general combat until they are gone, my troop could easily take care of the ressurected troops after most of his army was gone. Cast Demon Portal by the crystal. Succubus', oh well, swap closeby dragons with royal snakes, let them smash the crystal.