The Dark Summoner Quest is a medium quest.  First attempt my sovereign, tank hero and two troops were all one shotted by a spell called despair (multi-target spell) cast by the Dark Wizard (instant cast - no chance to interrupt) who also has high initiative so only my sovereign got to act before he nuked me.

I need more hit points and resistance I thought, so leveled my hero's to stack those stats and trained up a big tough army able to tackle strong and deadly quests.

Attempt 2 the Dark Wizard one shots my sovereign (so much for stacking resistance), reduces my tank hero to a couple of hps and nearly half my troops hps are wiped out.  I charge forward killing his wildlings and enter melee with the Dark Wizard.  Troops miss but my tank lands a hit but barely scratches him. Dark Wizard casts despair a second time, my tank dies and my troops are reduced to a few hps.  Their attacks barely scratch the Dark Wizard and they will be wiped by the next despair spell so I hit auto combat to end my misery. VICTORY - huh.  No wounds for my dead heros in fact they get exp points and level and no more troop loses.  I also get a bad ass Golem unit called Bill as a reward.

I guess spell casting doesn't work for the AI during auto combat but still not sure why my dead heroes got exp, maybe for completing the quest but then why no wound?