So, for survival mode. Your buff and debuff effects don't wear off at the end of each fight. You can survive pretty much indefinatly by taking advatage of this. First three classes that stuck out are ranger for the health regen. Conjurer next for summoning wargolems and ageis for increacing survivability, important to have revive too. And here's that fun one, mage for front center to take all the hits, arcane armor last till they die, and you can cast flickering flames on the whole party for complete 100% damage reflect. Last I went with the rouge for theif's luck, which improved ensorcelled blade and rain of arrows to near 100% accuracy. Health regen is the best thing ever equip to recover a third or their health each round and you won't need to heal. Conjuror needs extra health, heath recovery, and stun resist so that you don't lose your ability to revive. Set your front to wargolem, mage, wargolem and revive them/replace them as they fall.