I won by simple endurance. I repeatedly nuked enemy units with Fire Rain, watched them get resurrected, and nuked them again, while steadily bleeding my unit numbers. Kharador ran out of mana and by ~turn 15 every enemy unit was dead, at which point I could simply Fire Arrow/attack the crystal.
Probably not the most efficient way to win, but it did work.
Mage 24
A5/D15/I28
LDR ~14000, not 24000
