Found out an easy way to beat survival mode. Ranger, Conjuror, Cleric, and Mage. Stick the Cleric up front and stack him up with as much armour as possible. Throw the rest behind him in whatever formation you deem fit. Make sure to get Swiftness from the Ranger, Electric Storm for the Mage, and Eldritch Aegis and Summon Wargolem for the Conjuror. Throw up two Wargolems right away, buff everybody up with Eldritch Aegis, Swiftess, Nature's Balm, and hopefully Arcane Armor for the mage. The only time you ever need to worry is wave 15 and 35 when Voidstalkers show up. Take them down ASAP as you don't want to be blinded. Before and after that, just outlast them. They can't kill so, so you'll end up whittling them down.
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