Play as a thaumaturge and repeatedly use the Blizzard skill. All enemies will take damage, not just those under the cloud. Construct as many traps as possible, focusing on one area of the maze. Consider using "monster in a box" type traps along with fire traps. After a total of about twenty five traps are ready move to the other area, with only a few traps placed there. The concentration of traps in that single area can take out all enemies. The remaining traps in your area should suffice to keep it protected for you to take out anything that gets through.