place the auras on the side of the stack or ogres can throw balls outside the range of the strength drain
waves 22-24 are extremely slow on this(around 90-100 seconds for me) but waves 25-34 shoot down to 45-60 seconds for me(wave 35 is around 100 seconds as well but the enemy count doubles so that follows)
aim the towers in the middle of the lanes so the mortars and clouds can cover 2 at once
w22 tb + upgrade + double huntress and monk
w23 upgrader can be changed to double apprentice or someone extra to level up