|“||I am free... at last. Mortals, before you die, know that you have pleased KAHRK, mightiest of the ogre magi. Your deaths shall feed my power, for now I am weak.||”|
As the fight begins, he casts Mirror Image on himself, then turns to offensive spells, including:
Waiting for the buffs to wear outEdit
This strategy requires some careful positioning of a single party member. Leave the party behind, take one character (preferably wearing the Boots of Speed) and slowly approach Carsa's location until she appears at the edge of the fog of war and initiates conversation. Then, once Kahrk appears and ends conversation quickly retreat to the party's location. If done correctly, the ogre mage will not follow. Then wait for around 5 minutes real time or sleep for 6 hours ingame and Kahrk's protective spells should have worn off. He cannot recast them, so slay him any way you want.
Kahrk's Minor Globe of Invulnerability does not save him from wands and higher-level spells (above 3rd level). Use Cloudkill, Flame Strike, Wand of Frost, Wand of the Heavens, etc. can dispatch him even with the protective spells on.
Protection from Normal Missiles does not affect enchanted arrows, enchanted bolts and enchanted thrown weapons (of +1 or better quality). It also does not affect elemental damage done, so Flame Arrows will deal only their fire damage. Use this to pelt Kahrk with missiles.
Arrow of SlayingEdit
The Arrow of Slaying is the ultimate anti-ogre mage weapon. A one-shot kill. There's only one of it in the entire game, though, so plan carefully against whom to use it. Kahrk is among the most dangerous ogre mages (if not the most powerful), so it might be wise to use it against him. Just make sure that Mirror Image is not active when you do.
Wand of ParalyzationEdit
The Wand of Paralyzation, found at the Lighthouse or purchased at Sorcerous Sundries, paralyzes Khark if he fails his saving throw (which, for me, happened on the second casting, before Kahrk got a shot off). (A dispel magic might have helped this succeed? It's not necessary, in any case). With Kahrk paralyzed, your party's melee attacks should land much more easily, his mirror images wear off quickly, and Kahrk should die without much trouble (my 5th level party of 5 dispatched him within the 1-turn duration of his paralysis). Using 1 or 2 of the wand's 13 charges (roughly 600 or 1200 gp worth of the wand's cost, or 300/600 gp worth of its salable value) is debatably a waste of money, but for those looking for an easy way, this worked well (and much more cheaply than an arrow of slaying).