I have fought this guy several times, trying several different strategies in Classic Mode, and he just won't die. He constantly heals. Is there a key to killing him?
@LordDragonOCT in the immortal words of Arthur (Monty Python Holy Grail) Run away Run away.
Joking apart that is how I beat him on veteran by running away.
I left the mage, cleric and thief at the bottom other end of the map. The place with the gap between to rock areas that cut away to the left and right at their bottom. Cleric and Necromancer in right cut away and Thief (using bow) in the other.
The two fighters went and engaged him when one got to about 2/3 health and one of his copies was dead they ran away. He chases and the fighters train him from one end of the map to the other all the while he is firing off spells most of which don’t hit.
Did two full circuits before the fighters ran down the gap. At the same time the Necromancer summoned some pets into the gap. The pets engage the train, when the train gets into the gap the fighters have healed up.
The Necromancer continues to summon pets into the gap, between pets and the fighters he and his copy never make it into the gap. The fighters beat him and his copy down the cleric heals when needed.
The reason I did it this way was that he seems to target the caster and thief with damage spells and two hits is normally enough to take them out. If he or his copy do manage to target one of them ducking back into the cut away puts them out of range of a second hit. Any pets he manages to summon behind the fighters between them the Necromancer, Thief and Cleric can take them out.
That was the tactic I used for this party it might not work for yours.
MC Fighter/Shaman/Winter Mage
But what ever party you have if they can summon pets then do it. Throwing pets at him is always a good tactic as he seems too always engage them before targeting your party.